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Why are you echoing? I don't know why you're saying that. Uh OK. Well, let's start and see how it goes. Uh OK. So we're gonna start off with kind of principles of tumors to begin with. And then we'll move on to talk about some of the intermediate lesions that don't quite fit into benign, don't quite fit into cancers. And we'll end today hopefully on some bone mets and then next virtual session, we'll predominantly talk about benign lesions and some of the primary tumors. OK. Uh So we're gonna start off talking about how to describe a bone lesion. So hopefully, um just to kind of reiterate it for ST threes, ST fours. So you get a good solid description of a lesion for when it comes to the FRCS and then how to go about investing someone investigating someone that you think has got a suspected sarcoma, how you go about doing a biopsy and actually what that means and then looking at how you stage someone and then how you actually go about doing the referral and what makes it good. So if you have somebody who's got a lesion in their bone on a plain film, you're predominantly going to be thinking about these three things. So is it benign? Is it malignant? And don't forget infection, especially in the pediatric population, you can get these epiphyseal based lesions that you might think are a tumor but actually um are an infection. Ok. So particularly in the exam differential, just don't forget infection. If you're thinking cancer, then obviously you're thinking primary cancers like sarcomas or bone mets, which are the most common lesions or something of a hematological malignancy. So again, you can structure your answer as to what your differential is and add those layers on in terms of malignant lesion. So the way I would go about describing these x rays with bone lesions is to start off first with skeletal maturity. So there are certain lesions that you're going to notice more frequent, frequently in Children and there are certain lesions that you will notice more frequently in older patients. So it automatically just gets your head in line with. Ok. This is a child. It's probably more likely to lead to be a Ewing sarcoma than it is to be a chondrosarcoma, which more likely is gonna happen in an adult over the age of 50. So it just sets the scene for yourself and the examiner. OK. So positive or negative finding as to whether or not there's open ps So um anybody out there, um I've kind of given the Ewings one away already. Ewings sarcoma is a childhood cancer. Ok. Chondrosarcoma. More common in those over the age of 50. Uh Any thoughts on adamantinoma, young adults. Yeah, young adults. Um kind of between the age of, kind of like 20 to 50 usually chondroblastomas, uh kids. Yeah, perfect. So, once you've kind of established how old they are roughly um move on to skeletal location. So you might have somebody with an epiphyseal based lesion and there'll be a set differential for those. You might have a metaphyseal lesion, it might extend into the epiphysis, er or you might have a purely diaphyseal lesion. Uh And the reason that's relevant is is that a lot of you will have already seen this diagram, which is in a lot of textbooks on or bullets and just gives you a rough idea of which lesions appear where. And again, if you're looking at, well, if we say here, child, they got an open pisis. Um You've got your chondroblastomas which are p are purely epiphyseal based lesions and don't forget infection because that might have come from the joint or go into the joint. You've got lesions that are predominantly metaphys. So these are the osteosarcomas, they don't respect any boundaries, so they will cross the growth plate. Um And then you've got your aneurysmal bone cysts again, unlikely that they're gonna cross the growth plate. Whereas in an adult, if you had a cyst that's arising in the metaphysis and it comes down and starts abutting up against the joint surface. That's your typical giant cell tumors that we're gonna talk about a little bit later on today. So, just based on that picture and where the lesion is on the X ray, you can start to build up a rough idea of what type of lesion it's likely to be based on the age and where it is. The other thing in skeletal location you can think about is where it's arising. So you could have a cortical based lesion, you could have a lesion that's occurring within the intramedullary canal or you could have er surface based lesions. So, if we think about cortical based lesions, um any ideas from anyone, things that just arise in the cortex, osteoid osteomas. Yeah. Perfect. All done. Anything else? Cortical based anyone? No fibromas? Yep. And when they're bigger, what are they known as fibrous dysplasia? Uh Not quite. So, a non ossifying fibroma is a fib like is an area of the bone that hasn't ossified. Ok. It's fibrous based tissue within the cortex. But a bit like when does a pond become a lake or when does the hill become a mountain at two centimeters? A non ossifying fibroma becomes a fibrous cortical defect, minor kind of nuance difference in the way they're names. They're the same thing though. So, cortical based lesions, osteoid osteoma, very painful, respond to nsaids. Um Multiple different ways of treating them. But first line often is nsaids, physiotherapy and then going up to radiofrequency ablation and we'll have a little chat about those over the coming sessions. Uh Benai non ossifying fibroma, fibros, cortical defects. And again, adamantinoma, we're gonna talk about them in a little while. They're incredibly rare tumors, but they're a very classic textbook uh tumor because they have a very certain area that they tend to form in. So, again, kind of very easy to start making up this differential diagnosis based on where it is intima lesions are going to be things like your enchondromas, your fibrous dysplasias and some osteosarcomas, we will probably in the next lot of sessions go through the kind of cartilage based lesions. But just remember enchondroma N inside. So N and chondro cartilage. So it's cartilage forming on the inside of the bone. Whereas if we look at surface lesions, an osteochondroma is bone forming uh with cartilage cap outside of the bone, people sometimes interchange these and get confused, but we're gonna look at some of them over the coming sessions this month, right? Uh And again, in the surface based lesions, you have things like parosteal osteosarcomas, which you see on the back of the distal femur literally look like a lump that's just been stuck onto the back of the femur. Uh And again, it's kind of a very classic x-ray that comes up in exams and in practice that you should be thinking if you see it once we've looked at the location of that lesion, you can start thinking about what it's made of. So the matrix and these are the kind of most common types of lesions. Lytic lesions in metastasis, for example, lesions, things that are stippled. What kind of matrix might that be that it contains kind of material? You mean like the you know, chondroid? Um Yeah. So it's gonna be cartilage base. So you kind of get this um kind of popcorn type picture where it's stiff for one of better word. Er and ground glass is more typical of fibrous space lesions like this um fibrous cortical defect. All right. And then have a think about what effect that lesion is having on the bone itself. Ok. And that might be that it's expanding the bone, it might be that there's endosteal scalloping and we'll come to what that looks like in a second. You want to look at how it transitions. So does it go from normal to abnormal very quickly or actually does it kind of fade out? And you can't really draw with your finger around the lesion? Not very clear. And is there any soft tissue component to it? So if we look at this one, you can see that the fibula has clearly expanded. Ok. So that would be an expansile lesion with this one, you can see that you can really mark out with your finger where normal and abnormal stops. And so you would say that that's got a wide zone of transition. And if we think about zone of transition, just to be clear that everyone understands it. If we say that green is abnormal and white is normal, you can very clearly see that we go from green to white and that's got a narrow zone of transition. Whereas over here, you can see that it just gently fades out and it's difficult to see where that light green becomes white. You would say that's got a wide zone of transition, ok. Wide zone of transition implies that tissue boundaries may not be being respected. And that that's probably more likely to be something sinister than something benign. Endosteal scalloping. So, if we think of scalloping as this kind of pattern, all right. Um Endosteal scalloping is when that occurs in the cortex of the bone. So you have this area where the cortex starts thinning out as an effect of the lesion. And you can see that in this X ray that the cortex has started to thin out, generally speaking, not a great sign, more of a sinister sign than benign. But you do sometimes see it with benign lesions like some enchondromas can do this. And then the final part is what response is the bone having to the lesion. And that might be that there's a periosteal reaction. It might be that you've got a fracture. What you don't want to miss in your describing a pathological lesion is the fact that there's an associated fracture implications for how they're treated and what their recurrence rate is like things like that. So, um anyone want to describe either of these, I'll take it out to um this ap radiograph of the, the distal femia in the knee on the right and the image on the left seems to be a lateral radiograph of the distal tibia of proximal tibia. Yeah, for different patients. OK. So I'll describe the one on the right first. So there's lots of uh so some sun uh appearance with periosteal elevation, uh there's a lesion. Uh So there's mixed sclerotic and lytic sort of picture of the uh bone itself of the distal femur, there's a wide zone of transition. Mhm uh Good. So yeah, so you can't really draw where this ends particularly. Well, can you, you might be able to hazard a guess? But it's not particularly clear and absolutely right. This, this is known as sunburst spiculation and this is a very particular type of periosteal reaction. Some people describe it as hair on end. Um but e either uh you might see in uh MC Qs, for example. And what would you say spot diagnosis for this fish? Osteo osteosarcoma. Yeah. So Sunray spiculation, classic osteosarcoma. All right. What's the difference between this one and the X ray on the left fish in terms of the periosteal reaction on the left one, it shows layers of depositing uh um which again, it has a narrow zone of uh uh it has a wide zone of transition and is like appearance of that. Uh If you had to pick, if I had to pick, what if you had to pick a vegetable that it might resemble onion peel appearance? Yeah. On. Yeah. Yeah. So a bit like peeling off the layers of an onion. This has got layers. And so what's that typical of fish? Ewing, sarcoma, ewing sarcoma. So if you see onion peeled uh perote reaction, you're thinking Ewings, but you wouldn't think Ewings for this, you would think osteosarcoma because of the difference in the periosteal reactions. Ok. Good. Um So I've got a few lesions. Um You don't have to be peri exam to volunteer. There's a lot of cases throughout these slides. So it's gonna get very boring if no one wants to interact other than vision. Ben. So if anyone wants to take this, you don't have to get the answer. It doesn't matter if it's right or wrong, but just to describe the x-ray, we don't have, we'll get to the kind of diagnosis in a bit anybody you want to go. Sure. Yeah. So is that um Tom, Tom. Hi, Tom. Sorry, I can't hear what. So, yeah, go ahead then, Tom. So this is a, an ap radiograph of the right wrist of a skeletally immature uh person. There's a uh lesion in the er sort of distal third of the um of the radius. Uh It's got a lytic appearance. There's endosteal scalloping. Um, there's an associated fracture. Um And mm. Yeah, that's it. Good. Well done. So, you've got the location, you've got the skeletal maturity. The matrix is lytic, isn't it? It might be a solid component here. Just kind of get a vibe that it's a slightly different color to down here, don't you? Whether or not there's something solid in there and it's got a narrow zone of transition. Yeah, exactly. So narrow zona transition, you can see where it ends and it becomes normal bone again. Yeah. The endosteal scalloping. So it's been thinning it out. So it's clearly been there for a while and then the effect on the bone is that there's a fracture. Um There's one kind of pathognomonic sign on here. Uh If anyone knows it. Is it a drop leaf sign? Yeah, exactly. Perfect. So, you've got a fallen leaf sign. So a bit of the cortex has fallen into this lesion and it's pathognomonic of any idea. Um I read about it yesterday. I, is it a UBC? Yeah, perfect. So, a UBC is unicameral bone cyst, but you can also call it a simple bone cyst. All right. Um So that's kind of a textbook. Um x-ray of a simple bone cyst and actually a lot of the times when they fracture, they go on to heal completely fine and the lesion resolves sometimes when there's a difference in the material that's in there So this difference here is that when something has been present for a very long time, they can start getting secondary aneurysmal bone cyst changes and sometimes you might start seeing little fluid levels. So just something to be aware of. Um, if it's been there for a long time, sometimes you do see that. All right, good. Well done, Tom. Thank you. Um I'll put the X ray up and then you can decide if anyone wants to volunteer. Uh This is the next one. Any takers uh I can do it. Go ahead then. Um So it's a ap radiograph of the left hip of a skeletally mature uh individual. It shows a uh lesion, uh a li looking lesion at the uh base of the femoral neck um that appears to be well uh defined with an Arizona transition. There's no uh obvious cortical reaction or uh soft tissue surrounding reaction. Um There's no fracture through it. Mhm What do you think it might be? So, if we go back to the location? So, this is cortical based arising, isn't it? So, it seems to have just been confined to the cortex. So, what might um we'll say that they're a 20 year old, they're getting a lot of night pain. Oh OK. So, so it is a osteoid osteoma. Good. So that's a classic history that I've had quite a few of these in Norwich recently, actually of like uh kind of 18 to 27. Year olds coming in with pain. Um, they're getting a lot of night pain, waking up, wake them up at night. They take nonsteroidals, it gets a bit better, but they're coming in because they kind of got to the point where that's no longer working for them. Um And so the next step up if nonsteroidals aren't working are talking about things like radio frequency ablations, you can put a needle into this area, it heats up, um, and it ablates that area. So there are some risks with it. Um, obviously risk of infection and there's limitations to when you can do it. So, um I've had a few recently that have been ulnar based and obviously, there's not an awful lot between the skin and the ulnar. If you're heating it up from the inside out, there's a risk of thermal burns if there's er, not lots of tissue between them. So this would be great for radiofrequency ab patient, but you just have to be cautious or warn them that there is a risk of burns. The other thing is that if it's near a neurovascular bundle, obviously, you don't wanna be heating up near that either and each probe that they put in is about able to ablate 1 cc. So obviously, if you've got quite a big lesion, um it depends on how many, er, that they can use in one go, but most of the osteoid osteomas aren't too big one or two probes. I think usually enough. One interesting thing with this X ray is that it's almost got the opposite of the scalloping, hasn't it? So the cortex has become much thicker on this side uh in response to the osteoid osteoma. And you can just see on the inside that there's kind of this fuzzy white isn't there around the inside of the cortex. And they actually can get quite significant periostitis in response to the presence of the osteoid osteoma, which I presume is because of the prostaglandins that get released from it. Um Although I don't know, you don't quote me on that. Um The kind of typical questions for osteoid osteomas is is that there is usually something in the center of the lesion. OK. We call it aids and the best way of seeing that then what kind of imaging would you get a CT scan? Yeah, CT scan. So the moment you've got the nidus there, that's the bit that produces the pain. You can make the diagnosis of osteoid osteoma, well done. Uh And next one for describing this one's a bit harder. V Do you want to do this one? Thank you. Sorry. Um So that's a ebx ray of the knee of a skeletally immature person. Uh whi which shows quite a dense sclerotic uh appearance of the proximal tibia. Mhm. Um It might be the X ray prance. I'm just gonna tell you that there's because it may not project very well. There is a lucency here. Yeah. So there, there's a lipid looking, uh, lesion in the, in the PS. Mhm. Uh, which does not seem to cross the, uh, so in the epiphysis, which doesn't seem to cross the FS, there's no obvious cortical destruction, the joint surface seems intact. Uh good differential, differential osteoblast, uh chondroblastoma. Perfect or particularly in the child around the point. Ok. Mm. Not the right age. Or just don't forget infection. Yeah. It's unlikely it's most likely chondroblastoma but just in, in a differential, I mention it. All right. So chondroblastoma pathognomonic of an epiphyseal based lesion that respects the piscis. Yeah. Yeah. Uh Good. OK. So they're the describing ones. Um Once you've obviously got a lesion that you're suspicious might be cancer, you want to start thinking about what you're going to do next and how you work this patient up. OK. Now, if you're suspecting someone's got a sarcoma cos they've got a lesion on their playing field like this one say um you want to start thinking about local staging and systemic staging within your local staging, you want an X ray of the whole bone. So if you've got this distal femoral lesion, you need an X ray of the whole femur and you want an MRI scan of that whole femur. And the reason you want the MRI scan is obviously one to see the extent of the tumor locally, whether it extends out into the soft tissues, whether there's any involvement of the neurovascular bundle, if it's say posterior, and you want to know that there's no skip lesions or which are a type of metastasis further up the femur because they're going to determine what or what you might not be able to do for this patient in terms of surgical intervention. Ok. So that's your local staging. Once you've got that, you also want to think about your systemic staging. Cos you want to know what's roughly this patient's prognosis going to be, have they got lesions elsewhere? Uh Is this something that I'm thinking might be curative resection or is this multi metastatic? Ok. Now, two ways of thinking about it most common when you're on call, you're probably going to have someone with a bone met and you don't know what the primary is, but from a sarcoma point of view. Um Oh, sorry, we'll come back to that in a second. Um Sarcoma's metastasized to the chest. So if you think that you have got somebody with a primary bone tumor, you're going to want a CT chest to look to see if there's any lung nodules or lung mets, if you're chasing where a primary is because you think someone's got a bone met. You obviously want to get a chest abdomen and pelvis to look for that primary solid tumor. Yeah, you then need some form of whole body imaging. Now, if you're in a tumor unit that might be an MRI of the whole body. But the reality is is that outside of a tumor unit, you're not going to get that done. So you would get a bone scan to look for if there's any other metastasis in the bones. OK? And I put in this area, don't forget to do myeloma screen if it's that you're looking for a cause of a tumor as opposed to it being a sarcoma and trying to stage it. Ok. Now, the reason I put this picture in is that this is an example of a skip lesion. So this is a met skip met and it's roughly around the 5% mark of er primary bone tumors might have a skip metastasis. So if, if, if you're thinking of resecting it, you want to include that skip metastases in your resection level. Yeah, which we'll talk about in a little while. So we mentioned some of this already. So you have skipped lesions which are metastasis that occur in the same bone as the primary lesion. You might have multiple bone mets. So it may be multiple bones involved. So you might have femur, you might have pelvis, you might have humerus sarcomas typically go to er the chest and more. So in osteosarcomas, about 40% will go on to develop chest mets, 20% in soft tissue. And there are a group of sarcomas that are notorious for going to lymph nodes. There's only a handful of them and although they're rare, they are very common. M CQ questions. So any thoughts from anybody about sarcomas that metastasize to the lymph nodes? Ewings? OK. Any more? Did it come up in your MC QV? Thankfully not. OK. So you can remember it as E SARC. OK. So, e and then SA RC. So these ones are the ones that will typically go to the lymph nodes. They're not quite uh Ewings but epithelioid synovial, the angiosarcoma rhabdo sarcomas and clear cell. So this um I did have this question in my M CQ. I think um there'll be like a, well, you don't have extended matching anymore, do you? But it was an extended matching and it was like which of the following tumors metastasized to the lymph nodes. So, um we just want to bear in mind, obviously, if you've got not got one of these sarcomas, then you wouldn't then start doing a lymph node examination because they don't metastasize to the lymph nodes. OK. So, uh we've staged, it's been through a sarcoma MDT. And we're going to start talking about doing a biopsy to get a diagnosis. So in the exam, you can very easily get asked what is a biopsy. And it's one of those things that if you haven't stopped to think about definitions that some of it sometimes they catch you off guard in the exam um because you just take the language kind of for granted when we use it day in day out. So how would you describe a biopsy? The biopsy is a sample of the abnormal tissue that you would uh take for further investigation to try and identify the his histological and uh morphological characters of the uh lesion that you're trying to identify. Yeah, fair enough. So, a medical procedure to obtain tissue for a diagnosis. Yeah, just try and keep it simple. It might be a biopsy for you could effectively take a biopsy to if you're doing cno biopsies for culture, for example. So, um you don't, yeah, it might depend on if they've given you a situation or not, but you don't. Yeah, you can say histology. It might be for culture. It might be for cytology. So don't dig yourself a hole. Just keep it simple. Yeah. So there's lots of different ways of getting a biopsy. Um, and we'll come to those in turn, indicate a biopsy. Generally speaking, something that looks aggressive on imaging is likely to need a biopsy, er, if it's been indeterminate on imaging. So the radiologist haven't been able to say what the lesion is. If it's deep to the fascia, it's got an increased risk that it's not, may not be benign more than five centimeters. Again, risk that it might not be benign and any solitary lesion that's aggressive in the bone and that's regardless of their history of cancer. So, if you have somebody that's got a known breast cancer and they appear on the take and they have an aggressive bone lesion and it's only one lesion within the bone. Then actually, there is an association, for example, with chondrosarcomas in breast cancers. So you would probably want to work that patient up, particularly if the breast cancer is like a previous history and it's not an active um condition that they're having treatment for. So types of biopsy, uh fine needle, not used that often in orthopedics, core biopsy used very commonly in Ortho and that might be ct guided if it's from the bone or it might be ultrasound guided if it's from soft tissue. And don't forget that if it's from bone, you're probably gonna need to do a G A because it's going to be quite uncomfortable to have a biopsy done. Ok. So that's where you start getting higher order thinking in your exam. You start saying, you know, this is a bone lesion would probably be a CT guided biopsy under general anesthetic. It just shows lateral thinking and the fact that you've kind of been involved in these types of cases or at least in the discussion. Ok. Incisional biopsies and excisional biopsy used. Both of them are used a little bit. Um but they're not kind of the preference. So we're just run through each of them. Um So this is a fine needle aspiration really common in the thyroid, really good. Uh If you're aspirating lymph nodes to get answers but you generally speaking, get a cytological uh answer rather than histological. And so there are some mixed advantages and disadvantages. They're really not used in sarcoma very often cos it's very difficult to get a definitive diagnosis that you can base treatment on. And so we would say it's more likely to be non diagnostic and you only actually get a definitive diagnosis in less than 20% of the cases. If you're thinking about sarcoma, in terms of advantages, it's it's cheap and it's relatively accessible and it can be done under ultrasound guidance and under a local anesthetic, but it might be cheap and accessible. But if it doesn't give you the answers, you're just losing time. Um So from a sarcoma point of view, probably the only time you would use it is for a lymph node assessment. Any ideas on what this is or what it's used for true cut biopsy. So you'd use this as a core biopsy. Some of you might have seen them in breast clinic in core surgery, something like that. Um And so what it does is as it goes through, it takes a core of the tissue. However long the throw length is of the needle. Um this is kind of your working work course, I guess uh for sarcoma diagnoses to begin with anyway, um much higher diagnosis, definitive diagnosis rate. Yeah, a histological answer as opposed to cell uh cytology and um compared to having an incisional biopsy, there's slightly less complications. Ok. Disadvantages are that if it's a small lesion, you may not be able to do a core biopsy or if it's near a neurovascular bundle, you probably won't be able to do it. And the risk of it being non diagnostic is quite slim. So you're only really looking at 5% aren't you or less. Um So sometimes you might have small lesions on the digits and obviously you can't do core biopsies for those. Uh So the alternative options are going to be things like incisional biopsies and excisional biopsies. So this is an example of an incisional biopsy where you have a tumor, but you've just taken like a little segment, wedge out of it and you just send that wedge off for histology. OK. Now, why, why would you want to do that if you think something's a sarcoma, say it's in the forum. So I got a pretty high suspicion. It's um a sarcoma. I can't do a core biopsy coss it's near a neurovascular bundle. So I just go in and I take a wedge out of it. Uh We, we'll understand that if you got a sarcoma in that compartment, you're probably gonna be taking out the whole compartment. It's only the risk of seeding these uh tumors that uh stop you from doing an incisional biopsy or uh cutting through the tumor. So I would still try to do, I would try to do a core biopsy if I could, but if it's near the neurovascular bundle, it's contraindicated. So, um, my alternative options are either doing an incisional biopsy or excisional biopsy where I take the whole lump out. What's the problem? If I take the whole lump out, I send it off to the lab and they say, yeah, it's a fibromyxoid sarcoma or whatever sarcoma you want to pick. Um, but I haven't got clear margins. What's the problem? So you need to come back to do a further excision? Mhm. And the problem is is that then it's, you'll have a scar in the skin, but you've got no real idea where that lesion was in that bed of in that scar bed have you because let's face it. We all know how mobile these things are, aren't they? So you'll end up taking a lot more tissue trying to make sure that you get a clear margin. Whereas if you just take a wedge out of the tissue, you've left palpable tumor behind. Once the sarcoma diagnosis is confirmed, you can then go back and do your planned um surgical excision with clear margins. 1st, 1st time around, it's less than ideal because obviously, it's two procedures and you are opening the tumor to take that wedge out. Uh but probably less of an issue than not knowing where the tumor was and trying to take uh resect new margins. Ok. So incisional biopsies, uh obviously, again, advantages, disadvantages, they're actually quite expensive because they end up needing theater time as opposed to it being done in like an outpatient setting, in radiology, slightly higher complication rate because it's a procedure. So potentially got a general anesthetic involved risk of wound infections. It takes a longer time to get the diagnosis because you're on a waiting, you're even on a cancer pathway. If everyone's on a cancer pathway, you still have a, a bit of a wait um to get into theater for. So to get a histological result from a core needle biopsy for a soft tissue, you'll roughly wait about eight days. But if you're waiting to have your procedure, uh your procedure and then your histology, it's about 15 days from an incisional biopsy. So it's a good week difference um between the two types. So just another advantage for core needle um risk of contaminating the field. That's obvious, obviously, because you're going down to the tumor to get it. Whereas if you are doing your, if you had a core needle biopsy and you're going back, you're going in to do your surgery as the primary time is being touched, you're never going to open that tumor and risk seeing it. Um advantages is obviously quite a small risk of it being non diagnostic similarly to uh cor needle biopsy. So I'd say it's kind of second or third line for sarcomas. This would be an example of the excisional biopsy. So the entire lesion just gets cut out. Ok. It's good if it's something that you have a pretty low suspicion of it being malignant. So, something that you think is probably quite benign, but you're just not able to tell on the radiology what it is. Again, small lesions that are superficial, probably lend themselves more to excisional biopsy. Um, disadvantages, same again, requires a surgical procedure. So it gives you a slight delayed diagnosis in the same way that an incisional biopsy would. Um And it's a bit more expensive than the core needle, but obviously they've had treatment at the same time. Um You do run the risk of having what we call an intralesional resection where you haven't got a clear margin and we're gonna spend a bit of time talking about what those different types of margin mean in a second. And we've kind of covered this already. It's difficult to know where that lesion was if you ever have to go back and do reexcision of margins, a second procedure. So you end up taking more tissue, you might end up taking more tissue than you needed to. Ok. Uh Any thoughts on this picture? So it's a clinical photograph of uh the thighs of uh a patient showing uh significant soft tissue swelling. Uh what was sort of swelling of the left thigh? Um No. Mhm Well, it's the, the thigh has expanded. There's no obvious overlying skin changes that I can see from the photo. Um It appears to be all localized over the distal thigh and maybe into the knee but nothing down into the um, the, the strain of the lower leg. Mhm. So this might be something like a soft tissue sarcoma. Ok. So quite a common presentation of soft tissue sarcoma. I'm gonna give you uh two incision choices, which would be your preference then purple or pink, if you're gonna do an open biopsy, uh pink. Oh no, not pink, purple, purple, then. So um cos that's er looking at the, where the lesion lies, it appears to lie in that longitudinal plane and that, that incision would be um extensile. Um So that you can uh take for, if you need to come back for to remove it for an excision, you can extend along the line of that incision. Um uh and also it would uh and you would stay in that one compartment rather than potentially having to see two compartments if you use the pink incision. Perfect. So um say we did an open biopsy, it wouldn't be necessary with this, but we're just going to say for argument's sake just to go through the principles you want approach that is going to be extensor. Ok. So say we opened this purple line up. I coming back for the definitive surgery would excise my biopsy tract or biopsy scar. And so to do that, I would need a relatively small oval that would likely get primarily closed if I had gone transverse, I need to excise the scar, but I also need to have something extensile because I'm never going to be able to get this tumor out through this scar. Am I even if I went all the way across her thigh? So you would need a much larger oval um incision to be able to get rid of that scar and you run the risk that it might not be um, primarily closable at the end of a case. I mean, thighs are pretty forgiving. But if you were doing this somewhere else, you would, you would struggle, wouldn't you? Ok. So, longitudinal in incisions that are extens are, that's the first kind of principle of biopsies if you're doing open biopsies. But even if you're talking about core needle biopsies, you want that biopsy site to be in the line of wherever the definitive extents are. Longitudinal incision is gonna be. So, next thing. So we're taking, we're, we're using the Ben's purple line. Ben chooses to put in a drain fish which, which drain site do you think he should use A or B B? It's in the same line as your same line as the incision. So that can be excised again along there. So you're just going to extend your oval slightly, aren't you? But again, if you go out to the side of it, your oval is becoming larger again to try to clear it. Ok. Uh Good. So what we're trying to get at is is that your approach should be extensile if you're having a drain, not very common, but if you are having a drain, it should be in line with the wound or within the wound. So coming out of, you know, coming out in the middle, you want to stay within one compartment because the last thing you want to do is seed tumor to normal tissue and you want to avoid a neurovascular bundle. Because if the neurovascular bundle gets contaminated, you may not be able to then salvage the leg and reconstruct. Ok. So you might end up with the neurovascular bundle is contaminated. The amputation becomes an option and these principles are predominantly all related to avoiding contaminating your healthy tissues. Ok. So when you're talking about your principles of biopsy in FRC S, you can say the principles of biopsy are to avoid contaminating healthy tissues by using an extensor longitudinal approach remaining within one compartment, avoiding contamination of the neurovascular bundle. And if using a drain, bringing that out in line with the wound. Ok. Why do we use drains um V in the principles of biopsy? Why? Why might people use drains into void? Seeing you wanna try and uh uh one get, get the best hemostasis as possible. And if there is a very leaky tissue, you need to have that uh draining out rather than collecting inside and again, the risk of seeding. Yeah. So what we're trying to do. Now is any we want really solid hemostasis. Uh So you release the tourniquet before you close hemostasis and a drain if necessary. And this is doing everything that you can to avoid hematoma. Ok. Hematoma in the tissues, you have to assume that that whole hematoma bed is then contaminated. Ok. So you, if you were headlining it, so you were kind of um uh kind of path uh pointing the examiner, you're wanting to avoid contaminating healthy tissues and avoid the formation of hematoma. And this is how you're going to do it. Yeah. Um The final principle, I've put it here, slightly different color is that you want area of tumor that's representative so often with a tumor, especially if it's got large like this, there'll be areas of it that become really necrotic. And if you biopsy that necrotic area, you're not going to see an awful lot from the histology report. So the, the reason for an MDT approach to the tumors is that a surgeon is there to talk about what their definitive surgery is going to be. So that you know where their incision needs to be and therefore know where your biopsy needs to go. But you also want a radiologist that can say this is a really good area of tumor to take biopsy from. This is not necrotic, it looks representative of the tumor itself because again, there's no point taking a biopsy from something that you're not going to get the answer from. So you need to avoid contaminating healthy tissues, avoid hematoma and take a sample from the tumor. That's representative. OK. So that's kind of my headlines for the principles of biopsy. And this question comes up in the exam, it came up uh in the previous not this setting that's just gone, but the sitting before. Ok. And these are very easy things to just roll off your tongue to keep yourself at a six and then you're gonna build on it to get sevens or eights. Uh Any any ideas on what this picture shows anybody? Yeah, they tattooing the uh biopsy. So yeah, tattooing a biopsy site. Why, why might you tattoo a biopsy site? So you excise it um excise the tract as part of the surgical resection. Yeah, good. So this has become a bit controversial. So some tumor centers are still biopsying uh are still tattooing biopsy sites. Other centers are not OK. Um So the question is, is it necessary? So this might be something that you wanted to bring up in your exam. If you're talking about biopsy principles, you might say and in the units that I'm familiar with, we, we have uh biopsy tattoos so that, that, that can be excised at definitive treatment. I'm aware that this has become controversial, but there is still in the literature, about 10 to 12% of tracts that are contaminated. Ok. And your contamination is more likely with an open biopsy than with a core needle biopsy. So, it's quite a big difference, isn't it? Like 30%? Down to 1%? And the local recurrence free survival. So ie no tumor at the site of biopsy or definitive surgery, um, was significantly longer for those who were sorry, significantly longer for those who did have biopsy tract. Um, tattoos. Ok. So, um, I think I know which group I'd rather be in. Uh And if there's an option of having the biopsy tract excised, my preference personally would be to excise it. So that's how you can balance your answer. That will take you up into the sevens and eights. So if you have been through, you've described your X ray, you've completed your staging, local and systemic. It's been through the MDT patients, got a tissue diagnosis. Um It confirms some form of sarcoma. Let's say that patient goes back into the MDT and there'll be a discussion with the surgeons, the radiologists and the oncologists about definitive surgery and adjuvant treatments. So, what are adjuvant treatments? Radiotherapy chemotherapy? Yeah. Is that correct? Oh, hello. Hello. Um Yeah, so great. Yeah. So things like radiotherapy chemotherapy some sometimes if it's a like a uh a Melanoma, it might be things like immunotherapy as well. Um And the question is, is this going to be upfront treatment? So, for example, uh you might have a soft tissue sarcoma that's really large and they decide if the patient's not in too much pain to have upfront treatment, to try and shrink it down so that the definitive surgery becomes easier. It might be that, um, actually a patient is having a lot of pain, they're going to have definitive surgery upfront and then have um, treatment afterwards. So, neoadjuvant upfront and adjuvant if it's just um, following the surgery. So just some, you know, words that you might see around on the letters that you get back from your local G units, for example. Um and then some might have a bit upfront and a bit afterwards as well as particularly if it's radiotherapy, uh say after a pathological fracture or something like that. OK. Um And then once they've had their definitive treatment, they'll go back to MDT again and then they'll rediscuss their margins. OK. So did we actually get adequate resection of this tumor? Uh And is there anything further that needs to be done? So, the sarcoma patients go through MDT at least three, if not four times. OK. So resection levels, we'll have a breakout threeish guys. OK. So uh if we say that this orange section is the tumor, the yellow section is the reactive zone. So you're not really sure, is it tumor or is it normal tissue? But it's usually an area of inflammation around the tumor. And then we'll say that the pinky color is quads muscle. OK. So we've got a soft tissue sarcoma within quads. So, if somebody's come along and they've taken this lesion out like this. So this is the section that's been excised. What kind of resection is that? Intralesional? Yeah, exactly. Well done fish. So, the incision has come through the tumor. This has been taken out. But actually, you've left about, you've left the tumor behind. OK. So this actually would be an example of an incisional biopsy effectively, wouldn't it? So you've taken some of the tumor out, but you've left it behind. So that's intralesional. Uh you've got a positive margin on the excised edge. OK. So you still got tumor present on the histology at the excised edge. So that would go back to have further surgery. OK. What about this one? So it's excised through the reactive zone but it looks like all the tumor has come out marginal. Yeah, exactly good. So you've got marginal resection. It passes through the reactive zone, it's not positive on the cut edge, but it'll be very close within millimeters of the tumor. OK. And the next one. So you've got rid of all of the reactive zone and a bit of normal tissue, a wide excision. Yeah, wide local excision. So hear that, don't you in breast a lot again? Um So you've got complete excision of the tumor and the reactive zone and you've got a cuff of normal tissue that has gone with that and that remains within one compartment. OK. Final type of resection here is where you've taken this. What would that be? Yeah. Would be around the clock. Oh sorry. Uh not correct en block. I was saying en block but that comes with the lymph nodes. Yeah, exactly. Yeah. So uh radical excision here, complete excision of the tumor and in this case, the entire compartment. OK. Um So they're the kind of things that you would start talking about again, kind of hitting towards level sevens of uh what kind of resection you're planning? Um And if you were to be given a histology report, how you might then describe that histology report back. So obviously, um the worse your excision, the higher the recurrence rate. So if you've got a marginal re resection, you're obviously more likely to have a higher recurrence rate than you would if you had a wide local way, you've taken out a good cuff of normal tissue around it. And the research said more than 75% for intralesional, but reality is is that it's already there. It can't recur, isn't it? So I think may mean more than 75% after reexcision of margins. But um yeah, bear just to bear that in mind. OK. Because the next question often is, and I actually got this in my MRC S of what are the poor prognostic features on this histology report? And they just kind of handed me this histology report to interpret. Um So if they can do it at Mr CSI don't think they can not do it at FR CS. So, tumor size is a poor prognostic feature. So, if you're over five centimeters, um and it's malignant, that's not a good feature. Uh your margin, we've already discussed and seen the numbers for that lymphatic involvement, important. Uh Obviously, it just shows uh local spread within the lymph nodes and vessels and risk of uh metastasis, doesn't it? Um anyone know about round cell components? Sometimes you see that on uh histology reports. Does anyone know why it's a bad sign may not? And they're more common to metastasize? Ok. Anything that says high grade, not a good feature and anything that says dedifferentiated again, not a good feature. It means that it's becoming difficult to tell uh what it is. OK. So you see this a lot with chondrosarcomas, they become dedifferentiated and have a very poor survival rate at that point. And tumor necrosis can be a poor prognostic feature. Does anyone know the context of that? Is that because the tumor has been growing very quickly, very aggressively and it outstrips its blood supply. Is that David? Yeah. Hi. Right. Yeah. Um So, yeah. So tumor necrosis is a, you know, suggests that the tumor has been around for a while. It's probably got quite large. But um often what will happen in an M CQ question is that you'll have um uh a histology report that might say 85% tumor necrosis. OK. And you think? Hm, that's quite good. Uh It's dying, right? Uh And it's often in the context of being post chemotherapy. Ok. So what you want to see is actually that the tumor is dying in response to the chemotherapy. So you see this in Ewings patients. Ok. It's often a Ewings question that comes up and they say 85% tumor necrosis rate after chemotherapy. But actually, unless you've got more than 95% tumor necrosis rate, it's only at that point that you start a survival advantage. So, although 85% sounds high, it doesn't confer survival advantage. And it's actually a poor prognostic feature that they haven't got at least 95% response. OK. Um And that's the classic M CQ question with regards to uh prognosis of Ewing's sarcoma uh on histology. OK. Did you get that vision in your questions or not? Did you get any Ewings come up? No, there, there wasn't a lot of oncology, there was a couple of things. Uh This is another common uh M CQ. I had this one come up when I sat mine uh the E classification. So just something to have a little read through by yourselves at some point, it's really straightforward. So basically, there are three grades first is low grade and it gets split into A and B whether it's within a compartment or outside of the compartment. Um You know, we say low grade, but realistically what does it mean there are some tumors that are just known to be low grade, but if you want a histological answer it's to do with the nuclear cytoplasm ratio. Ok. I don't think anyone will ever ask you that though outside of a tumor unit. Um, and then we move on to grade two, which is your high grade and guess what? They get split into A and B and then we move on to grade three, which is the most straightforward one, the moment there's a metastasis, it becomes three. OK. So any grade, whether it's high or low with a metastasis grade three, eakin classification. Uh and again, this used to come up as an EQ. So I don't know whether it will feature quite as much now in the SBA world. But um yeah, it was very common beforehand and you'd get like five or six tumors and have to grade them. Um It did come up in my tumor station in my FRC S as well. So it's worth looking at relatively straightforward to remember. OK. So final bit before we stop and have a quick break. Um in terms of a good tertiary referral, the most irritating thing when you're accepting these tertiary referrals is if it's not, if the pathway hasn't been completed. So it hasn't got the contact details to be able to come back to you with a outcome or to ask for some further scans. So um make sure that you've got your details on it as what I would say, or at least the consultant's details so that there's continuity there for the team that are accepting the referral. Um in terms of what you're referring to the tumor units. If a sarcoma is, is suspected, that's a straightforward um referral, isn't it? If you've got an isolated bone lesion, again, that needs to be referred to a tumor unit or to someone with a specialist interest in tumors. Um, mainly because you're looking at, is there some, is there a survival advantage to this being treated as a metastasectomy? If it is a met, if it's an isolated bone lesion and you're not sure what it is, then obviously you're kind of treating that as a suspected sarcoma. And if it's something that you're unable to obtain a radiological diagnosis of, and there's still suspicion, then you would probably refer that as well, wouldn't you? Um The main thing that they want to know about uh in terms of their past history is, are they on anticoagulants? Cos they're going to try to sort out a biopsy most likely and you need to get all of the imaging linked with the local reports. And sometimes you just need to be very clear about what your question is because you may not be asking for them to take over care. It might just be that you want a radiology review of, you know, cartilage cap osteochondroma is, is this at risk or, you know, and that could be managed locally. It so just be very clear with what it is that you're looking for from the Sarcoma team because they get inundated with referrals to try and make sure that it's there and kind of all spelled out for them. Ok. Any questions about any of that so far? Silence to me. No. Mhm. No, thanks. That was really good. Ok. So that's just basically a run through of uh principles of how to describe the lesion. Some terminology around talking about cancer based side of things because we don't use these terms very common. Do we in our day to day practice and TNA? And then uh just how to work these patients up. So what we'll do afterwards is we'll do a couple of just brief fiber cases and then we'll start on the intermediate types of lesions. OK? So just grab a quick drink because I think it's gonna get boring listening to me talk otherwise uh let's come back in 10 minutes. Yeah. Have a stretch of your legs. So 10 minutes and um we'll do the next step. OK. OK. Are you guys back ready? Yeah, we was that a volunteer to or ready? Bye bye. It's far easier. So it's better to go first. OK. Good. Shout. All right. So um we're gonna keep it simple. We're just gonna split this one patient up into multiple fibers. OK? So it's a 50 year old. Woman, she had breast cancer a year ago. Uh she was treated with a wide local excision uh of her right breast. Uh Lymph nodes were negative at the time and she comes to the acute on caller referred by A GP because she's having pain mobilizing for the last two months. What do you think about her x-ray? How would you describe it? Mhm Lesion in the, in the trochanteric region. Um It's got a narrow zone of transition. It's lytic. There doesn't appear to be any uh endosteal scalloping or any bone reaction and there's no fracture associated with it. Um It's taking up more than 50% of the um of the width of, of the bone. Um I would be suspicious for either a metastasis or a or possibly a primary bone tumor. So I'd want to stage this locally with um uh first I'd get an X ray of the whole of the femur and a uh CT chest, abdomen pelvis to look for any other metastasis and an MRI of the whole of the femur to check for any skip metastases. Good. Perfect. Ok. Um Any blood tests you want to do? Uh Yes, I would do some routine bloods uh including uh CRP and ESR to just to rule out infection. Um And I'd also do a myeloma screen. Perfect. What other kind of higher order thinking blood test you might choose to do in someone who's got bone Mets. Oh Bone group, see if there's any evidence of hypercalcemia. Perfect, good. So again, another kind of seven for lateral thinking of uh treatment of other conditions that might appear like hypercalcemia. All right. Uh Lovely. Uh Thank you, Tom. That was your lot. Yeah, of course. Um You said about doing a whole femur X ray. Um You're not going to want a whole femur MRI. Anyway, um Tom's already put that in there. The reality is, is that, uh, you might see a, a lesion down there, they might have a knee replacement in. So, um, just a whole x-ray, a whole bone X ray, then the MRI is going because it's unlikely that you're going to get it the same day. It might be something that you can start already. You know, if you see all straight away that there's other Mets down the femur, uh, you might start thinking myeloma, you might get a hematologist involved. You might start doing blood films or it might be that you're like, hm, it's already multimetastatic in this one. Femur, isn't it? So, um, yes, you could say if you were being a purist of trying to save expense, you don't need it. Uh, but the reality is is that you won't get everything done on the same day and it might help guide other investigations like the hematological side of things or thinking about what surgery you're gonna do next. So, we're going to come to that in three as to what's, what might be done for this patient and what challenges you might face. So I'm looking at this thinking, there's a challenge I might face that I want a long leg film for. So we'll say five or three for you then. Thanks. Well bothered. Ok. Uh Who would like to go next? I'll have a go next. Who is that? Is that ok. Well done. All right. So what we're going to say now is how would you plan to obtain a tissue diagnosis from this patient? Uh So after MDT discussion and referral to a tertiary center, uh we'd want to rule out uh met, I'm assuming that is a primary tissue diagnosis would be from a um, bone biopsy, likely uh a core biopsy, I would imagine. Um-hum. Yeah. So, um how are you going to get it? So, bone biopsy, um you obviously you need some form of imaging to know where it's coming from. So, would that be ultrasound or CT CT? And it would need discussion with the interventional radiology as well? Yeah. So in the MDT, you've got your radiologist and you've got your surgeon. So we're probably thinking, hm, what kind of surgery is this person going to go ahead and have? So I'm going to say to you that it's an isolated um lesion, it turns out it's a sarcoma, let's say on this occasion, uh or the suspicion is that it's a sarcoma. And so they're going to go ahead and have a proximal femoral replacement at some point. So, where would you roughly put your biopsy tract? Do you think that's going to go through the front, through the side posterior? So, uh the things I'm thinking about is seeing tract and if we, if he's having a proximal femoral replacement approach will likely to be posterior, I imagine, although I haven't seen it myself. Right. So I would want the tractor to be posterior because then that tissue will be taken out anyway. OK. So a bit like uh a hip replacement, although uh a hip replacement is a well, not all hip replacements, my hip replacements, a lot of them in this region are posterior, the incisions on the lateral side, isn't it? Of the hip and curves around? So it'd be like that for APF R. Um So you probably have a lateral based biopsy tract. OK. So you can excise it when you come around to your surgery. OK. But that's the kind of conversation that goes on in the MDT is like, where are you going to put your definitive surgical incision? OK. I can access a representative tumor through that tract. Yeah. And I'll draw arrows on it that are saved on the radiology imaging so that there's proof for the next person that comes along to do it. Uh So CT guided biopsy. Absolutely because you want to know that you're getting that lesion because it's intramedullary, isn't it? So, you want to know that you're definitely targeting the lesion and going to get something representative. So, ct guided bone biopsies are painful. So, patients probably going to need to have a G A to have that done. Yeah. Yeah, good. So, uh one of the principles you've already mentioned uh is that you're talking about planning your biopsy tract. So what are the principles of that biopsy that's going to take place uh regarding the principles you'd want to make sure uh as in this a longitudinal incision. Mhm And make sure that uh it's avoiding any neurovascular bundles. Good. And um II know we discussed tattooing as well, but I don't know if that's relevant here mainly. Uh If, if we think that there's gonna be a hematoma, we'd want to put a drain in line of the wound. A good and extensive. Yeah. Well done, Keith. Um Vish. Do you want to practice for your exam that's coming and just run through the biopsy principles as if you're answering an FRCS question? Yeah. So the principles of biopsy would be that I would want to try and uh limit the, the seeding in the compartment. So I would want to take the uh shortest track which is directly uh approaches the lesion. I would ensure that I'm taking the sample from the appropriate tissue uh was location discussion. After the end, the discussion with the ne uh I'll also uh make the biopsy in the tract of the expansile uh uh incision that I'm planning for the surgery or have that discussion with the. Uh Usually it should be the operating surgeon who should plan the biopsy as well for the same reason. Uh If, if there's be any drains that we inserted, I'll put it at the end of that uh long incision. Uh But again, sorry, that comes more for the final surgery. Uh I will also want to take uh uh a try to avoid uh contamination of the compartments to go to as less compartments as possible without crossing compartments, avoid neurovascular bundles. And I would like to take a sample from uh area which is the the which is representative of the tumor. OK. Good. So kind of signposting summary to the examiner is going to be avoiding contamination of healthy tissues, avoiding hematoma and uh obtaining sample from a representative area of tumor. Yeah, everyone happy with uh principles of biopsy. Yeah. Can I just ask a quick question? So you go and you do a core uh biopsy and then when you do the tattoo, the tattoo tattoos the entire tract all the way down. No. So just tattoo the skin where the needle entered. Yeah. Yeah. OK. And then you kind of ellipse around that when you do your definitive incision. So it's just to remove the skin or no. So as as you go down your wound, you will continue in a straight line of um the biopsy tract. Yeah. So you could imagine that there could be some deviation of the direction that the, uh, the needle gone in. But in theory they're 90 degrees to the direction that they've of entry, entry point. Sorry, I have to spit my words out. Ok. So, um, you don't just take the skin, you try to dissect that whole area out down towards the tumor? Ok. Yeah, that was my question. How do they make sure that they get the tract out? Yeah, if it's not. Yeah. So it's dissected down any more questions about uh biopsies. No. OK. Ben. Uh Mainly because I know that you've seen P FR S before. So the patient is offered a proximal femoral replacement. OK. What might be the degree of resection that you expect for this patient? Um So I'd want to plan it on the uh MRI scan. Um But I would, it looks like it's the lesion is located just in the Peric region. So we'll say that there's nothing, no skip lesions on the MRI. Fine. So you want to give a good margin, um a resection margin. So uh a couple of centimeters below the distal extent of the lesion on the MRI. And then I plan my resection level off that measuring off the greater tranter so that I can measure it intraoperatively. Um um Also considering the section, whether I can take off part of the greater counter to reattach as an ab to um reconnect the abductors to the new proximal femoral replacement. Um-hum. Um Do you think you'd be able to with this case? Uh Probably not. No, probably not. I think it's too close. But yeah. So what Ben's referring to is that sometimes you can take a slither of the greater tranter so that you can attach the abductors for some function onto the um implant using bone. Uh If you can't, you just take the abductors off and you would suture them on either to a tumor tube or directly onto the implant. Um The problem is with this one, if you think it's a sarcoma, you haven't got enough margin there to take uh a bit of the tranter and keep it. If it was a uh a metastasis from say, uh breast or prostate, something like that, you might want to just keep like a, a tiny slither of bone attached um onto the implant. But for a sarcoma, this wouldn't be enough margin. All right. And the other thing that Ben said is that Ben saying he would measure from the greater trachaner to the tumor with his um additional margin. So that also is determined in the MDT. OK. So the radiologist will tell you at what point the bone goes back to normal with no signs of any tumor. And then what they give you is a transection point. So the transection point, the point at which you cut the femur measured from the greater trachaner. OK. So you're aiming for a wide local excision bend. So you're wanting your normal cuff of tissue, aren't you? OK. What might be the challenges in this patient of a proximal femoral replacement? Looking at this, they've got a very narrow canal, very, quite thick cortices going to be all the way down to the diaphysis. So you're gonna need a very well, you, you can the stem, I don't know what size the stem is, but you want to measure to ensure you can get an adequate stem down uh the femur. Um So that's gonna be a particular challenge, that part. Um I don't think your resection level is going to be too challenging. You're not going to need a massive proximal femoral replacement, minimal resection. Looking. The the other challenge looking articulately is that they look like they've got some element of, of degeneration or ra of the hip. Um So it's whether you, what head you're going to put on your um uh prosthesis, whether you're going to do a sort of a bipolar hem or dil total hip. Yeah. Good. Try and reduce that risk of dislocation um Along the themes of dislocation. What one other thing on this plain film is a little bit, you know, something you want to take into consideration when you're planning your P fr they've got quite a big offset, they've got quite a big offset. Yeah. So you're a bit limited with your P FRS, you don't have as many offset options as you do for a total hip replacement. Uh And again, so just summarize ben in terms of stability of APF R, what are the kind of things that you can do to try to improve your stability? Um So there, there's all the standard things as well, patient factors, surgery factors and sort of implant factors. We you mentioned about offset and balancing that thinking about um the the modularity of the implants as, as I said, using a dual mobility or um bipolar uh head on to try and reduce it. Um good soft tissue reconstruction if possible. Um Obviously, that might be challenging with the resection that you're taking and whether you're having to take any um soft tissue alongside the bone with this. Um mhm I suppose then postoperatively patient compliance and rehabilitation and ensuring hip precautions and adequate rehab afterwards. Yeah. And now I think you're gonna be restricted in what you can actually. Um Well, I suppose, yeah, cut position if you're putting an acet. Yeah. So exactly. So your uh all your normal instability factors apply. So your cut position, the orientation, you know the version of your proximal femoral replacement, your patient factors, your soft tissue repair, you might uh you definitely want to talk about hip precautions in this kind of situation with a proximal femoral replacement. Uh Some people might brace a proximal femoral replacement afterwards. So that might be something that you can talk about why uh soft tissues heal uh the actual state of the abductors and whether how easy it is to repair it back onto the proximal femur at the end. And then you can talk about your kind of other implant factors. So things like your head size, your jump distance, the use of dual mobility, whether that's dual mobility cups or using kind of bipolar heads. Uh in terms of thinking about your higher order, thinking of how you're gonna make this proximal femur uh less complicated for a patient? OK. But does that make sense why the long legs still quite relevant in the same way that you like your long leg plan, your X ray planning for a hip replacement or it obviously just that your hip replacements stop quite high up, don't they? Whereas your proximal femur, you've got to get quite far down and sometimes you're even past the isthmus and your, you know, your resection level, you're thinking about custom implants, things like that. So um same principles apply from that point of view and I don't think you get quite as good feel on an MRI scan about offset and the tightness of the canal, right? So you might want things like flexible reamers available uh for a tight canal for a proximal femoral replacement. OK. Any questions from anyone about those three? No. OK. Uh Let's keep going then uh we'll ignore that I had one already, Miss Pacey. I can hear me? Yeah. Uh Just a question regarding this previous case. Uh So if we already know that the patient is called AC a breast, uh would you still go ahead and plan a biopsy before you plan APF R? And so if somebody that's got a history of breast cancer, that's old, not the patient, their diagnosis is old, then I try, I keep, I would discuss them as a new patient as a new diagnosis, potentially because what you don't want to do is assume it's a breast cancer and it turns out to be a chondrosarcoma. If it's that they've got active breast cancer and the radiologists are happy that it's a metastasis and there's, you know, there's multiple metastasis. The chances are it's bone mets, isn't it from breast? If it's just one isolated lesion, you would generally still work them up. And the both guidelines suggest, would suggest referral mainly because if somebody's got one bone met and you give them a, you give them a enblock resection of their proximal femur and you build them up up with APF R, you've taken their disease burden down to just their primary tumor because you've excised their one metastasis and it becomes a survival benefit to them of having that done. Um So it's very much a balance. If somebody's multimetastatic, then, you know, chances are, it's just their breast, it's unlikely that it's a multi metastatic chondrosarcoma. If it's just one lesion, you want to prove that that's a bone, uh a breast met to the bone. Um, and think about survival if uh resecting a Met brings them down to just their primary disease. Ok. Sure. Thank you so much. Yeah. No worries. Ok. So, uh intermediate lesions are slightly odd in the sense that they don't quite sit in the benign category and they don't sit in the cancer category, but they've got features that sometimes make them behave like cancers. Ok. And, er, there's one very common one which we pre predominantly speak about and it's featured in the exam, er, in the last, not this setting cos I don't know kind of things that have come up but in the previous couple of settings, there's been questions on these, so histologically they're benign but their behaviors can sometimes be malignant and sometimes they do transfer form into malignant lesions. And that malignant behavior is, is that they can metastasize. Ok. Generally speaking to the lungs. Ok. Um Anyone else peri exam that's signed in? That's not vish. No, let me double check. Uh this. Do you want to do this then? Yeah. Yeah, go ahead then. So it, it, the uh X ray of the, of the hand which shows a lesion in the distal radius, it's a slightly mature individual. Um There seems to be some ballooning of the distal radius um with the, it, it's a narrow zone of transition with a mixed sclerotic and lytic sort of uh picture. There's no obvious periosteal reaction. Um It doesn't seem to uh breach the joint line or the cortex. Mhm What would you be thinking? This might be? Uh So, so it has some septic and uh a sort of film uh ground glass sort of an appearance to it. So it could be a fibrous lesion or a sim simple bone cyst. Ok. So these lesions kind of uh again, kind of not quite pathognomonic but quite typical that they are metaphyseal and they extend right up to the articular surface. So they're periarticular lesions with this metaphyseal extension. OK. And they're often acentric. So it's kind of heading towards the ulnar side of the radius, not fully into the radial side of the radius, isn't it? So it's acentric, it's periarticular and abutting the articular surface. OK. And it has, I agree with you. It's got this kind of septal er appearance to it, hasn't it narrow zone of transition? And it's expansile any takers? Giant. Yeah. So giant cell tumor of bone. Ok. So that's that kind of classic description. Periarticular abutting the surface they're centric and they're expansile. OK. And when you open these up, they genuinely look like scrambled egg. OK? Um So you can kind of think about the septations as being the bits of the scrambled egg if that helps you remember it, but genuinely it is basically a grayish yellow color, scrambled egg that comes out of them. OK. They're just mush Um, so symptoms generally are pain. They might have uh kind of a very slow onset, typical night pain of any of these lesions are generally painful at night, aren't they? Um, they'll notice swelling. So they'll have swelling predominantly on, often on the dorsum of the wrist because obviously you've got less tissue there. So you notice it sooner. Uh They might have an associated joint effusion. Rarely, they'll have a soft tissue component, but predominantly that swelling is due to bone expansion, they'll become stiff because of the, the effusion and because of the pain and if it's affecting lower limbs, they might present with a limp. Ok. Particularly around the knee. In terms of investigations, you're obviously gonna get an X ray of the painful area. MRI scan. I think these things go without saying. But why might people, er, think about getting calcium levels to be checked? What might this mimic parathyroid tumors? He said that Paget's disease. He's a parathyroid. No fun. Oh, well done. I, why did you say that? What, what's that kind of tumor called? Oh, you're correct. It's a brown tumor. Yeah. Brown brown tumor, well done guys. Ok. So, um, G CT should always have a calcium checked because if you have a, uh, hyperparathyroidism and you have a brown tumor that can be treated entirely medical by treat medically, by treating the hyperparathyroidism. Ok. So any GCT should have a calcium checked as well. Um, and then you're still gonna go down the same route of your biopsy, same principles, same discussion with the MDT. Um, but you're also going to do a chest X ray and if that shows anything, a CT scan, just to confirm that there's no, uh, metastases present at the time of diagnosis and they have ongoing chest surveillance afterwards to ensure that they don't develop chest um, metastases. Ok. Um, well, we covered that already. Yeah. When you're doing the investigations for brown tumors, you do only have to do a calcium level, you don't have to check the parathyroid. Uh And once the calcium is high, then you speak to endocrine. Ok. Ok. So coming back to this one. All right. Uh What we went ahead and did is what we call a curettage. Ok. So this patients, it was slightly expansile, but they'd got good bone stock left. Uh I say good. It's all relative, isn't it in tumor world? Um So you make a trap window, lift it up and then you get in and you correct out the area and all you're doing is you're scraping out this scrambled egg, ok. Uh And then what you're left with is a big defect. Ok? And you've got this cartilage layer that obviously you can't see on the X ray, but it doesn't have very much support behind it. So you then need to bone graft that area so that the cartilage doesn't sink down and then you're going to pack it out with cement and it's got two reasons. Cement produces heat. So any residual cells that might be left behind, hopefully uh are affected by the heat from the cement. But also it creates um it prevent the bone graft, prevents the cartilage from being damaged from the heat of the cement as well. Ok. And that's what it would look like afterwards with the cement packed in. Ok. You can, some people do graft them but the risk of recurrence is greater. OK. So in terms of higher order thinking for the exam, if you're thinking about what makes a good curettage and how you're gonna go about doing it. Um, again, extensile approach because you're always planning for, OK. What if this fails or what happens if they have a recurrence? You're going to make a trap door window to get in, but you mustn't forget to cure at the back of the trap door. OK. So the last thing you wanna do is put it back on without having er, debrided the trap window, uh thorough curettage, which basically means you keep going until you really can't keep going. So every time you think you've got it, you will continue to find some more and you need a really good range of sarcoma curettes that have got variable angles that you can get into all sorts of nooks and crannies. You might want a high speed bear as well to break down some of those septations that again, you can get in and make sure that you've taken all of that scrambled egg type, er, tissue away. You need II to make sure that you've got into the nooks and crannies and you kind of save a picture at each point with the curette so that you can show that you've been there, um, change the diathermy setting over and coagulate all of the inside of the cavity. So that again, you're using heat to try to prevent any cells from, er, causing a recurrence. Some people use phenol and some people use liquid nitrogen, but I think the evidence for it is very mixed. So in Stanmore, they don't use that, they predominantly go on diathermy. But I think, think, and don't quote me, I think some other places, er, for example, Birmingham, I think might still be using, um, but I think it's personal preference and probably what, um, what your experience is with the way that you're doing them, what your recurrence rate is probably will influence that, won't it? So, be aware of the other things that exist for the exam, but that it's, there is some controversy around it. Um. Ok. So that's the good curettage and that kind of higher order thinking of how you're going to go about doing it if you're wanting to talk about it in exam. And just as a, some people struggle to kind of get their head around what this looks like you've, uh, got your lesion here, you've already curated it out. So you've got this layer of bone graft with a layer of cement behind it and that offers the heat and some structural support. And if you think that there are a fracture risk, you might then do an additional or if, ok. So, and you can drill through the cement as it's going off to get that screw in. That's probably more common say around the knee. So if you're doing um curettage and grafting, er, of say a lateral femoral condyle, probably a bit more likely to put the plate on uh just as extra support. OK. Um Sometimes there's staged management of these. So um there is some medical treatment that can take place so you can convert what is uh kind of soggy scrambled egg into what becomes like cement? Ok. And that's with treatment of denosumab. Does anyone know what Denosumab is? It's a monoclonal antibody to rank ligand? Perfect, well done. Er, so, exactly. Right. So uh I've got some slides in a minute with the um way the osteoblasts and osteoclasts interact because uh some of the ST threes and ST fours, er, may not understand that yet. So we'll talk through that in a second how it actually uh has effect. But the advantages of turning something that is er, very soft into that kind of concrete texture is that if you're wanting to do a resection and cut that bone completely out much better to do it with something that is solid and therefore not likely to contaminate the compartment. Ok. Er, and that might be the case if you've got say a distal femoral lesion and you want to treat it, turn that into concrete and then do a distal femoral replacement rather than a curettage. Ok. So we're gonna come into that in a minute. Um So just to kind of go through, does anyone want to talk through it from an exam point of view? Basic science or? No, maybe not. So, osteoclasts are the special cells that are resorbing bone and they're under the influence of lots of different signaling pathways. OK? I'm not gonna talk through how the osteoclast works cos we cover that in the basic science term, but that's just a reminder of some of the words and if you're not familiar them, just spend a little bit of time maybe reading Ramachandran uh on that section just so it makes sense. OK. But all we have is the osteoblasts over on the left and they directly um trigger the osteoclasts by parathyroid hormone. OK. And that's by producing rank ligand. Now. Oh, what have I done here that activates the osteoclasts? And that allows the bone to be resorbed. OK. Now, if you have a monoclonal antibody to rank ligand, you have exactly the same process going on. But the rank ligand no longer works cos it doesn't fit the receptor. And so the bone doesn't get resorbed. OK. And so you're gonna have something that's much more solid. And then obviously that's how they also use it for kind of endstage treatments for osteoporosis as well, don't they? Ok. So Denosumab is quite useful. They, sorry, they don't use it for osteoporosis anymore cause you get a rebound osteopenia. Oh, thank you, Tom. I read about it the other day. There is something else that they are using, Isn't there for osteoporosis? I can't remember what it's called. Were you reading? Is it teriparatide? I didn't read that far. I think they might have replaced denosumab with teriparatide, but I can't remember how that works. It can be your homework, Tom. Uh OK. Who wants to uh describe this one? I'll give you a hint. It's the same diagnosis. Yep. Uh So this is a ap and lateral radiograph of the left wrist of a skeletally mature individual. It shows uh a lesion in the um in the metaphysis which is expansile abutting the joint surface. It's uh it appears lytic with septations. There's um I think quite a narrow zone of transition um and there does appear to be some periosteal reaction. Mhm Good. So nice description. So it mainly being expansa abutting the articular surface extending into the metastasis consistent with giant cell tumor? Um What's the difference Tom? Do you reckon between this one and the case that we saw previously? Do you think this one? You could cure it? And graft. No, there's, it doesn't particularly uh sort of on the ulnar aspect, but also dorsally and vally there's no real cortex left. No, it's really thinned out, isn't it? So, you haven't really got anything to pack against, have you? But also do you think the patient's going to be happy with like that big bone expansion being packed and leaving, being left there? No. No. Exactly. They're still going to have symptoms like this patient had some median nerve symptoms. Um Where else it's expanded quite anteriorly, hasn't it or vally sorry? Um They'd also got painful range of movement in their wrist because they're developing arthritis where everything's thinning out. So uh curettage is kind of off the cards for this patient. So what other options might we have? It doesn't have to be you to anybody. Yeah. Uh I mean, you could do a uh an excision of it. Um And then um yeah, so I suppose you could do uh uh like fuse it with a, with a bone strap, like a fibular bone strap. Um-hum. OK. Fibular or there could or, or whether there's a distal radius, replacement, hemiarthroplasty or? Ok. So in the world of uh tumors, there's custom made everything. So yes, you could do distal radius replacement. They generally don't have great uh outcomes and these are generally like younger patients. So you want to give them something that's got some bone stock for the future for you to fuse onto in terms of carpal fusion. OK. So you mentioned fibula. Um and you mentioned, I think, did you say allograft? I can't remember you said fibular graft, I think. Yeah. So what kind of fibula would you use? A? Um Oh Yeah, you were one. Yeah. Yeah. So from the patients. Yeah. OK. So um yeah, I'll show you the pictures. So that is what we did. So again, with these, you treat them with the denosumab so they get hard. So it's less likely that you're gonna poke a hole in it and contaminate the field. Yeah. So period of denosumab, then you're gonna resect the abnormal bone and while you're doing that, the plastic surgeons are very kindly raising a vascularized free fibula from the same patient. OK. Now, uh oh, did I put the pictures on this page or not? Yes, I did. So this is down the road and it is not a great out wasn't a great outcome for the patient, but we'll ignore the fact that that's gone wrong. OK? But what happens is the fibula gets turned over the plastic surgeon. You, the orthopedic surgeons will do the orif and reattach it, compress it. The vascular surgeons plummet back in, OK. In terms of the wrist, you have to leave for want of better words from Gristle, on the disc, on the fibula so that you can uh again, I guess for want of a better word, cobble, the ligaments back together again, that you've been able to preserve because there's a lot of attrition with the expansion of that giant cell tumor. So you make what, what you can out of the lesion, uh out of the soft tissues that you've got to make the wrist stable and you'll probably put some K Ys in to stabilize the wrist to begin with. Now, the long term problem of this over the coming years is, is that you'll see that the drudge is obviously understandably not functional. And that doesn't usually cause problems until further down the line. But you can see here on the lateral that the carpus is coming off the back now, isn't it? So at this point, patient will go ahead and then have a, a fusion of their wrist. Um But you've probably got them about five or so years down the line with a relatively well functioning wrist like um this chap before it had got to this stage, had returned to playing his guitar and things like that, uh which he probably would have struggled with a custom to store radius. Um And you've still got those options down the line if you still need them. OK. So this is just about trying to give them some bone stock for a future wrist fusion. OK. You probably could argue why don't people just fuse it straight away. Um But it's a kind of step wise in a young person of trying to give them bone stock and give them movement for as long as you can. All right. But again, this could very easily show as an adult path case. You know, what are you gonna do with this kind of situation? All right. I think they would be very cool to kind of give you this, but they could definitely give you that expanded giant cell tumor and get you to talk about curettage uh versus kind of reconstruction and how you might go ahead about doing that. OK. These are quite rare cases, but they do sometimes appear um giant cell tumor around the wrist, definitely appeared uh last year. Um I just have a quick question. So if it, so you do your, you do your um calcium level and it's high and it turns out to be a brown tumor. Do you still do curettage? And no, no, they have like medical management of their hyperparathyroidism and you can do interval imaging of the lesion and you'll find that it starts to resolve. Thank you. No worries. Any takers on this one looks slightly different, doesn't it? So, uh ap ap view of the knee which shows uh area of slices of the proximal tibial on the lateral side of it, there seems to be a fracture in the lateral tibial pa. Yeah, but it's not very clear. So I'd probably want to get some more further imaging for this as well. Uh uh area and along the proximal uh later later of the tibia which have fractured or in uh gone across the joint surface, there's cortical thinning lot as well is a wide zone of transition. So my further investigation for this would be one to get uh further x-rays a second view and then x rays of the whole bone and then a further lo local staging with the MRI of the whole tibia. I would also like to get uh distance staging by doing a ct chest, the pelvis to look for other primaries. And my simple uh primary blood investigation would be full blood count, urine electrolyte, uh infection markers, crp, um bone profile and along with that group and say for further operative planning, OK. Fine. So uh this is what the MRI scan looks like. So we kind of come back to that appearance of, I don't know if it's me or not, but on that MRI scan, it kind of gives the appearance of that scrambled egg texture that it has. OK. So you've kind of got these mixed densities within it. OK. So this is a pathological fracture through a giant cell tumor. OK. Uh And so the conversations that happen when you have a fracture, the concern is that the fracture hematoma causes contamination in this case within the joint because it's intraarticular but then also within the soft tissues. OK. So the risk of recurrence in someone with a pathological fracture, regardless of what it is, you know whether it's GCT or, or um a, you know, sarcoma is much higher than if you don't have that fracture contamination. Ok. So most of the time when you've got a pathological fracture in the giant cell tumor sitting, you would probably talk about uh resection and endoprost prosthesis as opposed to fixation, curettage, cementation and um fixation. Now, obviously, you still have to have that conversation with a patient. This guy was a young policeman on his feet a lot. And so wanted to take the risk of recurrence over having in this case a proximal tibial replacement because let's face it. They're not a particularly satisfying operation. All right. But he understands how does the resection endoprosthesis uh clear up the contamination of the soft tissue in the joint because even so to do the endoprosthesis, then we can still divide it without putting endoprosthesis. I'm I'm just, yeah. So if you've got a joint contamination and you're doing a proximal tibial replacement with that, you would end up um resurfacing the femur. Ok. So you will have debrided the joint, you'll have debrided, the cartilage on the bone. Uh and you would do a tumor approach and debride the tissues around the fracture bed. It's not perfect, but it is more of a debridement than you would achieve, doing a fixation and preserving the joint. Thank you. OK. Um Oh, sorry. So again, this chaps you can see there is this lighter gray here, which is all the bone graft and then you have the cementoma behind it and then the fixation that's taken place. OK. They haven't quite managed to capture the that fragment of it, but the fracture actually extended down here. OK. So that's curettage cementoma and fixation. So, pathological fracture, just remember, contamination uh and the recurrence risk increasing conversations around uh fixation and reconstruction with endoprosthetic. OK. That's probably true of most of the pathological fractures. So if you were talking about this in a metastatic setting, like breast met, that's fractured, you might be starting thinking about postoperative radiotherapy to try to reduce contamination of the fracture uh hematoma field. OK. Um So just acknowledge that there will be contamination with a pathological fracture because again, that's just that higher order thinking uh any thoughts on this one and how you might manage it. So this is a sagittal and uh ap uh view uh of the at the line of the distal femur what appears to be a lesion and it's a oh sorry, it's at one weighted MRI scan. And there appears to be a lesion in the patella on the proximal pole. Uh with uh a small zone of transition, there appears to be a sclerotic lesion in, in the middle of that uh in that circumscribed uh uh lesion as well and it is abutting onto the anterior surface of the femur. Yeah. So this lady's already previously had G CT in her patella and had had one curettage and then this is actually her recurrence. So what kind of treatment options have we got for her? Um So she already had a curettage and didn't work. Ok. So we need to identify why, why the recurrence has occurred. How did we not clear everything? We need to read the operative notes. We need to then start from the beginning in terms of a full work up blood uh blood profile, calcium level, et cetera and MDT discussion. Um from there on, in um it's, if re resection that hasn't happened, there has not been any endoprosthesis used, possibly going down that route is a lot better before er, once we've cleared out any um um any cause for the recurrence. Hm. There's not an awful lot of her own patella left. Is there on, on this? If you look at the axial here, you've got a small bit of patella left, but actually the whole length of the patella is affected, isn't it on, on the Sagitta that you've got now? So, um curettage is not really an option because it's expansive. She's got a lot of patella, femoral joint pain. So curettage isn't going to really work again for her. We've already biopsied it and checked that it's not got a malignant transformation. So we're happy that it's uh standard GCT. Um So the only real option I haven't really got an end of resect the patella. Yeah, you can take the patella out. Ok. So this lady had a patellectomy uh as a result of her recurrent GCT, I think it was actually her third recurrence to be fair question because one, this is a recurrence and two, it's sort of obviously uh extending well beyond the patella. You, you worry about the intercompartmental seeding of that uh as well and contamination in that compartment. So if, if it's broken, if it had broken through the patella, you would be. yeah. What, what about doing a total knee replacement with a Pathom? And I know they don't have a good outcome, but along with the py, but I guess if that you, you, if you brought that up in the exam, you'd have to be very confident about talking about how you're going to mitigate the complications of your total knee replacement in the presence of a pect toy. Um They, I think that would be fair game if you brought that up. I would keep it quite simple in this situation. So um the MRI scan had suggested that it hadn't, it was still contained within the patella. Um She's obviously previously had surgery, but the windows had already always been on the external surface. Uh So it hadn't been a risk of breaching that was known on any of the eye, eye, eye images that he had reached the joints. Um And it's a conversation with the patient, isn't it about having a pasi is quite a big operation, having a pasi with a total knee replacement comes with quite high complications. Whereas if she ends up with a recurrence, um, the surgery might still be the same, isn't it? Um, but I think when this one actually came out the surface of the patella, she still had got some cartilage over it. So it hadn't, actually, didn't seem to breach the cartilage. And again, when it goes off for histology, you get that answer back, um, with regards to whether or not you've got a breach. So you wouldn't necessarily have to rush in and do all of that in one go. But you could discuss if the margin came back positive saying actually we think you've got a high risk of recurrence and talking about a further surgery at that stage. Yeah, I probably wouldn't rush into ap pall with a TKR. I'd, I'd, I'd say as a stage procedure, I think in the exam. Sure. Ok. No worries. Ok. What on so on the whole, they're benign but they're locally aggressive. You can see they don't, their, their expanse expanse are, they have a lot of symptoms for these patients. The risk of them transforming into a malignancy is less than 1%. But if somebody comes with increasing pain, they need to be rescanned, uh, recurrence rate around 20%. Um, so reasonably high, isn't it? One in five, some of them are actually malignant and at the biopsy, it will say it's a malignant giant cell tumor and uh just under 5% of those will have lung mets. Ok. But they are most common around the wrist and the hand, the malignant versions. Ok. Um And again, I mentioned earlier on, um when something's been there for a while and has been slowly expanding, you can get secondary aneurysmal bone cyst changes. And that's when you might start noticing that there's more of a soft tissue component on the MRI scan around the expanded bone. Um I don't know why that happens, but it is just something that they go hand in hand with one another. And therefore, you will probably need to excise that soft tissue component as well as the bone, right? Um This is all getting much of the same, but it's just another example. Um this one was actually a malignant giant cell tumor uh that came back on its bone on the bone biopsy. Ok. So this patient went on to have a distal femoral replacement so that we could excise the malignancy. Ok. And um for any of you actually are interested if you're seeing anything in clinic. Um There is the London Sarcoma uh service, you can just find it on the on uh if you do a Google search London Sarcoma Service surveillance. And um you'll be able to see the surveillance program for people with malignant GCT S for sarcomas, the frequency at which they should have their chest x rays. Uh So final summary, mostly benign locally. Aggressive. Don't forget they metastasize, do the chest screening, check your calcium. So you don't miss a brown's tumor. Don't forget the MRI scans in terms of what, how you're going to treat them. You're thinking of curettage resections and reconstructions. Um And we've kind of discussed those already about how you go about doing them. They're predominantly in people in their thirties to fifties. Uh in general, they're around the knee, but the malignant versions are a bit more common around the wrist and don't forget they can affect the spine. Ok. Any questions about G CT S? Yup. No. OK. We're getting close to another break, guys. We'll just quickly go through this. Um Anyone wants to describe the lesion, just simply describe the lesion. Oh, it's supposed, I'll have a crack. Oh, yeah, go ahead. Uh So this is um a lateral radiograph of the tibia of a skeletally mature patient. Um I don't know the clinical um vignette, but the location is in the um diaphysis or certainly in the meta region um proximately and er it uh is a lesion which appears to be coming from the cortex um but has expanded into the um medullary canal. Um The appearance of it is a um a septated lesion with no um periosteal reaction or certainly not that I can see on my screen. Um Yeah, so I'd be, yeah, want to see um another um an orthogonal view. Um I would obviously take a history and do an examination, I'd then be looking to, um, consider the appropriateness of a CT chest abop Pelvis, um, MRI of the tibia, er, hematological by chemical investigations. And then, er, depending on those, um, looking forward to an MDT and, um, biopsy. Perfect. If you had to hazard a guess at what it might be. Nick. Any ideas, I gotta be honest. No, don't worry, we're gonna discuss it. All right. Uh, any takers out there for what the diagnosis might be the mean to name it. Fibrous dysplasia, fibrous dysplasia. Oh, some people going for fibrous dysplasia. Ok. You, uh, Tom, did you say adamant? IMA? Yeah. Yeah. Why do you think adamant because they're always in the tibia in the exam questions? They are always in the tibia and they're often at the front of the tibia, aren't they? Yes. So, why might it not be fibrous dysplasia? I don't know. Ok. Who, who went for fibrous dysplasia? Some, two people said fibrous dysplasia. I didn't catch who it was. Yeah. Well, why might you, why might it not be fibrous dysplasia? Oh, II thought it was just because of like a picture I've seen before. I, sorry, I didn't catch that. I think you broke up. Mature. Yeah. The age, isn't it? So, um, fibrous dysplasia is predominantly intramedullary. Not so much cortical. And then there is a condition called osteofibrous dysplasia. O FD. And that can occur in the tibia, but it is more common in Children than it is in adults. So that's where it comes back to just having uh kind of just keeping it in the back of your mind about skeletal maturity, age location. All right, osteofibrous dysplasia uh comes up in M CQ questions because they really like the histology of it. So um very briefly if there is osteoblast rimming in a histology um report it's osteofibrous dysplasia because osteoblasts are producing bone around the fibrous dysplasia. Ok. But it's for some reason, a very common histology question to come up. Uh But Tom takes uh the cake on this one. Unfortunately, it is an adamant. Ok. So adamant are have this bubble like texture, ok? Or appearance, I guess it's not texture. Um And so you see all of these little bubbles at the front of the tibia, OK. And extreme versions of it is is that it can extend further down the tibia, it can start to cause bowing. You do see bowing very commonly with fibrous dysplasia. And so the differential including it is perfectly acceptable, particularly if it's a younger child. Ok, will be correct to say that osteofibrous dysplasia or fibrous dysplasia should not have that ballooning of the bone. Um So fibrous dysplasia, you do get bowing. Um in terms of saying a differential for this osteofibrous dysplasia is fine. Uh But I would say that you'd expect it in a younger person. Ok. Um Anyone know the relevance of either of these two pictures, I was gonna say, I didn't know, I didn't think I was real well. It depends, I guess on how, how much you believe. Uh So uh why, what's that picture then? Keith? Oh Wolverine uh holes are made from a originally bone bone. But after anyway, yeah. So yeah. So uh yeah, related and any, any takers on the bottom one? Anyone like Lord of the Rings? No, also made of adamantium. Uh OK. So this is just a little bit of trivia for you. OK. Any ideas on why ademas affect the mid anterior tibia? Because it is like uh Tom's right. It's a very common question that there's a lesion in the, in the front of the tibia and it's an AIO in MC QS. No, it is quite niche. So it comes down to embryology. Um and it's thought that basal epithelium is displaced, it takes up on the anterior surface of the bone. And so you get this on enchondral formation of the basal epithelium. Uh whether that's true or not, I don't know. But that is the theory behind why it seems to involve the anterior tibia because we all know there's not an awful lot between the tibia and the skin in that layer is there. And there's not very many other places in the body where it's quite so the bone is quite so prominent isn't all right. Uh differential. We've kind of covered it, osteofibrous dysplasia, probably appearances in the cortex, you could say non ossifying fibroma and fibrous cortical defects, infection. You know, again, it's a superficial area. You could have penetrating trauma and osteoid osteomas because it's cortical based, but it hasn't got that typical osteoid osteoma uh appearance has it of a lytic lesion with an nus um histology. Again, they love these questions in the MC QS. Um When I was doing it a few years ago, there was a lot of histology in there. And the key bit to, uh, Adema is this palisading nests which are these kind of uh long columnar cells that are palisading around. So, going around in loops. Ok. Uh You won't get given the histology picture in the MC QS, but there'll be something documented that's about palisading and you'll know that it's the adamant oma. Uh Again, another example where you've got it just at the front of the tibia there and treatment options are resection. So this gets known as a shark bite. And obviously you can imagine that there's a weakness there, potentially. Uh So they might go, oh, sorry, I just skipped way too many. Uh With this might, you might do a shark bite, keep them on weight bearing. You might shark bite them, do an allograft and plate it. Ok. Uh Other options are to have, I guess this is just another picture show you a slightly different uh, appearance to the typical ones. Uh You've got some changes there posteriorly as well. With this one, they've had um an allograft and plating a bit like the case before. So, resection graft and plate, other options are to roll. So you can resect their fibula, keep it vascularized and roll it, docking it inside their own tibia. And then you can supplement that with allograft struts from Cadaveric tibia. Uh and then again plate it. So, um for example, in Stanmore, if they're doing these kind of cases, they will get a size matched tibia uh from the bone bank flown in and then they will take out the graft that they need to supplement it. OK. And that will be matched uh to that uh the don, it will be donor matched. So, any questions about that. So the idea being that you're the abnormal bone, can we go back to the picture uh before this, when it show the distal tibial lesion? This Yeah. Yeah. So um lesion there's a lesion in the anterior cortex as well. Yeah. So this is the lesion that's been resected at the MDT. It was decided that this wasn't actually related to the adamant oma. So this part of it was ignored. OK. Um But I've just used it for the X rays POSTOP more than anything else just to show that this one's got an intact fibula. So you can say that they've had some form of graft because you can see the graft there. But you know that it's not their own, it's not their own vascularized fibula. OK. Uh Whereas the next one, you can, for the high road thinking you can say that the fibula has been used as an autograft as a vascularized autograph. OK. You can do inter calorie prosthesis. So these are sometimes custom. So to remove just this uh area of affected bone and then to do an inter calorie prosthesis, OK. Uh It might be that it extends quite high up. And so you might have a joint sparing, proximal tibial replacement. So this is a custom made implant. They've spared say the top centimeter and a half or so of tibia, they've got their own joint that's preserved and then they've had this custom made uh subtotal proximal tibial replacement. Um They keep the ligament attachments of their own joint. Ok. The patella is attached, patella tendon is attached onto the implant itself. You can imagine that that's not um an easy operation to recover from, but it is about preserving bone and then future proximal tibial replacement and distal, you know, um hinged implant will be their next step when this starts failing. Whereas in a young person, if you go straight to a proximal tibial replacement with a hinged knee, you've not got an awful lot of things left to keep going to have you. So it's always about trying to plan best surgical intervention from a tumor point of view balanced with what's our next step when this fails uh, quick question. How, how do you actually design the custom made implants? The CT scan again? I don't know if that was crackly for everyone, but I think, um, Keith, you said about how do you get custom made implants? It's all CT driven. Yeah. So the engineers will create a 3d custom implant for you, Missy, Miss you. Is it crackling for everyone or is it just me? Yeah, everyone is great. Mhm. Hm. I think that was it, Nick. Can you just try talking for me? Is that? Yeah, that was it. It's almost sort of echoing at the end of it. You've gone off mute now. You can't mute. Miss Space. I think you've gone off mute. You're on mute. Good space. We, we cannot hear you. Check the track group. She said 10 minutes. Let's just take a 10 minute break. Everyone sign out and sign back in again when you're ready. 10 minutes. So 20 past four. Ok. And then hopefully the line will be a bit better. Ok.