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That's good. Can you guys see slides? Uh Yes, we can. Thank you very much. OK, guys. So basically, I thought what we would do is cover um things that really are very common in the part one, but then also come up as pathology in part two as well. I obviously can't cover every single different type of tumor, but I will at some point before I sign out drop into the chat box. Um A good website. Uh It's an American website, but it's a really good website for details on different tumor types and you can just kind of go through that at your own pace. OK. All right. So this is gonna predominantly be a lot of pictures, a lot of cases and just discussions. So anybody would like to describe the lesion on the X ray. Um Obviously, we, we talked through last time about how to describe lesions, things like that. So anyone wants to take this one? It doesn't matter if you do or don't know what it is. I can, I can go OK, great. Who, who is that? Sorry? Cause II don't see. Oh, hi Marice. Go ahead. OK. Just describe the x-ray. Uh So this is an ap uh radiograph or sle mature patient with no patient identifiable data. Um What I can uh see is a lesion on the right side of the femur, it's the proximal third. Um it has a narrow zone of transition. Um It looks like a mixed lytic and potentially sclerotic lesion. Mhm um in the femoral neck uh and the proximal third of the femur. Um there is no obvious periosteal elevation, I think. Good. Yeah. Um And there is 222. What else is there? Um There's no obvious fracture that I can see good, well done. So, remembering kind of the effect the lesion has on the bone. Um What do you, if you had to guess what it might be made of, what would you say the kind of matrix is, would you say it looks more cartilage based or it might be a bit more ground glass? So it might be fibrous. What would you, what would you go with? I want to say cartilage based, but I'm probably wrong. Oh yeah, that's all right. 5050 go. Right. Uh So my next question to you is, can you see it anywhere else in the X ray? Is it just in that right? Proximal female? Uh It is on the right sided iliac wing kind of area? Yeah, exactly. So there's a, there's a section of it up here as well, isn't it? Um So, yeah, I'd agree. With you that up here, it's got, um, kind of a seemingly narrow zone of transition. You can kind of draw around it. It might have a narrow zone of transition down here, but you haven't got the full length. So I can't actually tell if it stops or not. And the other side looks normal, doesn't it? Yeah, on that side. So we've got two bones involved, maybe even a bit in the acetabulum. So more than one becomes poly and we've got two bones. So it becomes polyostotic because we've got these lesions in two different bone areas. Any ideas? What you think it is Marius or you can phone a friend, I can phone a friend. Um, any friends you wanna hear this is the kind of ground glass appearance down here. I was thinking neurofibromatosis. Yeah. Ok. Close. Yeah. Fair enough. Uh So, yeah. So I kind of go with the ground glass down here being something fibrous and we've got polyostotic. So any more advances, guys, polyostotic fibrous is it, is it fibrous dysplasia? Yeah. Cool. Is it Tom? Yeah, it sounds like Tom. Cool. Yeah. So polyostotic fibrous dysplasia. So, why is that relevant Tom? That I'm saying it's polyostotic and I've put the picture that's there on the right? What, what same patient, what might this be? Um, like a syndrome related? So, what, what kind of lesion is this? Uh uh no, I can't remember the name. It's kind of thing isn't it. Yeah. It's a cafe. Yeah. Which might have triggered the neurofibromatosis comment earlier. Why is it not neurofibromatosis? David. What kind of cafe AU is this? There's two different types? Mm II can't remember my Yeah, you don't see these ones very often, do you? Um So it's got this really jagged edge. Very rough. Yeah. And so there's two different types of cafe Ole and they're based on their sh how smooth their surface is and we'll come to that in a second. This one is a coast of Maine. OK? So it's got a really ragged edge. And if you look at a map of Maine, it has a really ragged edge. OK? And the way I used to remember this and it may not help you guys, but I'll just share it anyway is that it's very ragged because it's got, it's very rocky. It's also a place that's got lots of lobsters and rock lobsters. So that was in my mind how I remember that. So jagged edge, very rocky. Main rocky, lobsters, OK? Whatever helps you to remember it. So cafe lay spots with a ragged edge and polyostotic fibrous dysplasia, er, associated with precocious puberty makes up a triad and gives you a syndrome known as Mao Albrecht's, which we're gonna talk a little bit about uh after this slide. So, fibrous dysplasia, the lesions are expansile. So you can see that this femur is wider than the one on the left. The cortex has become much thinner. Ok. Again, got quite thick cortices on the left, haven't they? And this kind of ground glass appearance of something fibrous, it can be monostotic, meaning it's in one area and that's it. And that's not associated with Maco Albright or it can be polyostotic involving multiple bones and generally on one side of the body. Ok. And that makes you a little bit more likely that it's uh, Maco Albright. Now, you might have seen some X rays of something that looks like a Shepherd's Crook where the femur starts to have a bow in the proximal third because of the abnormal bone that's present there. Ok. So Shepherd's Crook, deformity is kind of very typical of fibrous dysplasia and really common in the MC Qs is that they love questions about what histology slides look like, not that they'll show you a picture in the MC Qs, but they'll give you um a description and ask you what it most likely is. And so in fibrous dysplasia, you get this alphabet soup pattern. Sometimes it's referred to as Chinese letters and it's just these really dense areas within the slide, you won't get the slide, it will be about the text. Now, we talked a little bit last time when we were talking about Adema and osteofibrous dysplasia. And we talked about the fact that if you have a slide or a histology report where it was to say alphabet suit patterning with no osteoblast trimming, then it's just fibrous dysplasia, but there's osteoblasts there, they're producing bone and therefore it's osteofibrous dysplasia. And that's a differentiating M CQ question, which comes up time and time again. Ok. So just to revisit Maco Albright, polyostotic fibrous dysplasia, precocious puberty and cafe ole spots. Ok. Now, the difference of the Cafe Ole is that these are the ragged edged m coast of Maine and in neurofibromatosis you get these really smooth er Cafe Ole and that's coast of California. Ok. So nice sandy beaches, all very smooth. Yeah, ragged edge coast of Maine in terms of the orthopedic manifestations of Maon Albright because of the deformity that the fibrous dysplasia can cause they can get leg length discrepancies or deformities and they can have a secondary scoliosis that forms, they might develop pain if they end up with a pathological fracture. And there is always, you know, in the back of your mind, if somebody with fibrous dysplasia develops pain to think about malignant transformation and they get MRI scans for that reason, but it's very low chance. Ok. So these are the kind of orthopedic things in a viva that you would talk about looking for if you had a patient with either the Cafe E or an X ray that you got given with a, a shepherd's crypt deformity. Ok. Um I think we've covered most of this already in terms of it being. And so that should say fibrous dysplasia at the top, not Maon or bright. Sorry. So if you have polyostotic disease, it's generally more aggressive. If you're younger with polys osto disease, you're more likely to get severe deformities, the more deformities you have or the worse deformity you have, the more fracture risk you have and the more lesions you have, the more risk of malignant transformation that you have. Ok. Now another common question that might come up in an exam is talking about using bone graft in these patients. And I've written allograft there. If you're going to use it, any thoughts on why you would have to use allograft in someone with er fibrous dysplasia, try to fill out the uh the uh basically the space for the cavity that's been created with a little lesion in order to increase uh stability and uh the stress. Yeah. Yeah. If you've curetted it out and you're wanting to give some strength back, you would graft it. But if you use the patient's own bone, it will get turned into fibrous dysplasia. Ok. So if you use allograft, uh so IE cadaveric bone, um it doesn't do it. Ok. So you have much more likely that your graft will take and stay. So, in terms of treatment options, if you've just got fibrous dysplasia or lacunal brights, um but actually you're not in pain, you've not developing deformities. Actually, you're just going to have ongoing observation, perhaps leg length me um measurements regularly. If your eyes are open. Ok. From a medical point of view, they often go through a metabolic bone unit and they might get started on bisphosphonates. If they start to develop pain. From a surgical point of view, we've kind of touched on already. It might be that they have lesions that need grafting and that needs to be allograft. So, any thoughts anyone on this patient's x-rays, unless you've been in Mister Sr Cos clinic and met this chap, then you can't comment. Can anyone see a shepherd's CRE deformity? Yeah. Um Yeah. Is this a corrected shepherd's crook deformity? It was an attempt I think at a shepherd's crook deformity uh correction, but the disease has continued to progress. So it's almost like it's continued to go round and the, the nail has cut out. So, Tom, do you know what kind of nail this is? Uh it looks like a, like a growing nail? Yeah, exactly. So they telescope on one another. So you have a female component and you have a male component, but you can see it's kind of threaded and screwed at the top and this distal component, you can't see it on the X ray. It's also got a thread at the end. So both ends are fixed, but the nail can telescope over itself. So it's growing OK. They're very specifically called Fazia Deva nails and you sometimes see them in patients with a um genesis infector as well. There can be a bit of a nightmare to get out because once you've managed to slide this end out, this is obviously still stuck down inside of the bone. So if you ever think you're going to take one out, there is a kit, there is kit to order in to remove them. Ok. So this chap came into clinic. He's 16 at this point and he's developed pain in his right hip. So what would you do for him? Can be anybody? Um So a known diagnosis of Maco bright, sorry, I should say. So, pain for this chap could be from a number of things. It could be metal work related. It could be because of malignant transformation of that lesion. Uh it could be uh like mechanical in nature. So, um you know, impingement from that or um or a sub subluxation of the femoral head. Um So I think in the first instance I'll do some uh some investigations. Um So I'll do some blood tests and uh make sure there's no infection of the metal work also do a uh a bone group. Um I would get some uh some further imaging of the, of the hip. Um And that would be I think an MRI scan. Um And uh yeah, that's probably fine. So the MRI scan comes back showing there's no signs of any malignant transformation and uh there's no signs of any fracture and he's getting mechanical symptoms in his hip, predominantly he's got abductor. Um deficiency and he is a wheelchair user but is able to transfer independently. But in the last kind of month or so, he's been having increasing difficulties being able to do that. And that's probably his main concern is that he wants to get his independence on transfer back. What could he have? Um So you, what you need to take that metal work out in the first instance and then you could, um do, I suppose like a, uh, an osteotomy, um, and uh to, to sort of vow guise the, the femur, um, and whether you try and take away some of that tumor as well. Yeah. So what we ended, we ended up doing for this chat was actually, um, excising that whole top end excepting that he had fibrous dysplasia that went further down, just excised the top end of the femur and he had, it wasn't quite APF R. So he ended up having uh a long uncemented stem and um, we used Cadaveric allograft. So he had AFA cadaveric femur. That is, it's a, when you use the bone bank for Cadaveric Whole Bones, it's a bit like um ordering from a, a catalog. Ok. So it comes as aged, er, not age match, sorry, group matched and um size match. So for height, if you're looking at femur, for example, so, um, he had a femur flown in from Barcelona and we shaped the top end of the cadaveric femur to fit over the top of the implant that we'd put in and then cabled it on as an allograft strut graft. And we had attached his abductors onto that. Um because obviously we needed to remove, we couldn't use any of his bone to reconstruct it because it would get changed by the virus dysplasia. And he hasn't really got anything big enough to be able to donate to the other area. Has he, you could argue proximal femoral replacement? Um, but obviously at the age of, uh, 1516 we were trying to give him some bone stock to work with for as long as possible. Right. So difficult case. Um, but he did quite well with it. Ok. So this is kind of the extreme version of Maco Al Brights and fibrous dysplasia. So I've put that in there so that you've seen an extreme shepherd's creek deformity and you've seen what fazio Devo nails look like? Ok. So it's just something to kind of pin that, er, case onto. Ok. Well done. Tom. Er, anybody out there coming up to their part one cos, I don't know. Well, unless anyone else knows the answer, er, of how it's inherited. Is it autosomal dominant? Nice. Yes. Er, se, because that would be the most common thing, wouldn't it, if you're a gambling person you would pick it, but not on this occasion. It's a bit of a trick question to be fair. Is it? It's not inherited. It's the orthopedic Oh, it said you, he's muted now. Yeah. So it's not inherited. OK. So it's a post psychotic somatic mutation. And so it's a form of mosaicism. OK. Um So it's, you have to remember it's not inherited and this does come up as an M CQ question, but it's also why it doesn't affect every single bone in the body. Ok. And it's an activation mutation which again is slightly unusual, not a deletion and it results in an increase in FGF 23 and minus that. Now, the bits that come up in the exam commonly is about the mosaicism. OK. And the fact that it gets to this point of having increased F GF 23 and that comes from this pathway here. So the gas mutation results in activation of GS alpha proteins increased um C AP and that all relates to increasing F GF 23 and fibroblast proliferation, which is how they get these fibrous lesions forming in their bone. OK. So, F GF 23 GS mutation mosaicism are the key parts of answering most of the MC Qs on um staff cover er on um fibrous dysplasia and lacunal brights in particular. OK. You could read into that in more detail if you wanted to, but it's not gonna, I've not seen it come up in the exam questions or UK questions um in more detail than that. OK. All right. So, uh anyone wants to describe the x-ray on this side don't worry about the MRI scan yet. It's not a trick question. It's quite similar to the last x-ray, isn't it? So, um this is a proximal, this is an ap radiograph of the left uh hip femur. Um II think it looks to be of a um scal scally mature patient. Yeah. Um In the proximal femur, I can see some um areas of what looked to be like uh lytic lesions. Perhaps you could describe it as mixed cause there are some sort of sclerotic uh areas. I don't see any um periosteal reaction. Um It seems to be sort of a uh defined narrow zone of transition. Um What do you think is happening to the cortices up here? Yeah. The thinning of the cortis is approximately. Yeah. And then do you, would you say it's ground glass again? It looks like ground glass? Yeah, I think so. And no obvious fracture there. Is there? No, that's right. No, it might be a bit up here. Um OK. Yeah. Yeah. So, uh if you're a gambling man, David, what would you pick? Um Sorry, I pulled a blank. Um Does it look like the last X ray? Yeah. Yeah. So what would you say it is? Um So I'd say that is uh fibrous dysplasia. It's another example of fibrous dysplasia. OK. Except in this occasion, the patient also had a lump in their thigh. Ok. So you've got a femur here and then we've got a lump that's intramuscular. Ok. On the MRI scan. And I'm going to tell you that, that histology from, that comes back as an intramuscular myxoma. So, does anyone know what kind of tumor syndrome you might have if you've got fibrous dysplasia and you've got multiple myxomas? You may not. But I, is it Mabra or Maz or something like that? Is that it's sorry? Oh, sorry. Hi. Yeah. Ok. So, um, fibrous dysplasia and intra muscular myxomas. Ok. So Mazabraud, this one doesn't come up quite as, as often in MC Qs. Um but for completeness sake. Ok. Now, generally the myxomas are on one side of the body and the patient has um fibrous dysplasia before they get diagnosed with the myxomas. So, I don't know if it's just that they're picked up later or if it's actually a temporal difference in the way that the disease progresses. Um If myxomas are excised, they very rarely recur they have got low recurrence rates and they very rarely transform into anything nasty or metastasized. Ok. So they're quite a benign lesion. And on a histology report, uh report, the classic M CQ question comes up as storm pattern, which basically means this kind of sometimes like referred to as a cartwheel where it's kind of this whirl. Ok. Again, you won't get the picture, but they'll sometimes use um the histology report. Oh, sorry, I skipped one. Did I do that one? Yeah. My bad. Sorry, everyone. That's not the Myxoma one. So I think I stopped there for Myxomas. So this isn't my, er, this is not a Myxoma. Sorry. This is moving on to it being a non ossifying fibroma. So I take that back, everyone. Sorry. Ok. So we talked about non ossifying fibromas last time. Um, anyone remember anything about non ossifying fibroma from last week? Um, I wasn't there last week, unfortunately, but I can tell you what I know that I know. Um So I think with non ossifying fibromas, they don't have malignant potential. So that's one of the key features of them. Um The other features are, they tend to be obviously quite well corticated. There tends to be kind of a sclerotic ring around them from what I remember. Um And I think often uh they can start off kind of near the metastases if I remember. Um and kind of migrate further down the diaphysis. Is that correct? Yeah. So position move and then, yeah, and then often you don't have to really do anything for them apart from obviously reassure the patient, reassure the family. Um Yeah, that was. So, um there are some associated orthopedic conditions with, er NFS and if you've got multiple of them, then it's Jeff Campanacci and it can also be neurofibromatosis. Ok. Um I think I covered this last time and I said to you, when does the hill become a mountain? And when you know, does a pond become a lake and it's a size difference. So, um enough, less than two centimeters. But if it becomes more than two centimeters, then it's a fibrous cortical defect. And I guess, logically that makes sense that if something's quite big and it's cortical based lesion uh that it would become a defect, wouldn't it if it was big enough? So, this is what uh cri was just kind of describing actually, isn't it? So, it's a cortical based lesion. It's a rising in the cortex, generally start off metaphys. OK. And they've got these kind of sclerotic rims. Sometimes people describe it as kind of a, a soap bubble appearance. You can kind of see individual bubbles almost in it, can't you? So this would be probably fibrous cortical defect looking at the size of it, wouldn't it? If you've got this patient here, they've got one in their tibia, they've got a small one over here in their uh femur, so multiple KNS and that patient would therefore potentially have Jaff Capar Syndrome. This one does come up in some M CQ questions because there are other manifestations that are generally not orthopedic. OK. They're more kind of heart eye and um developmental. OK. Um They sometimes might ask you that you've got this patient, who are you, who would you refer them on to? And it might be uh that they need pediatrics for kind of cardiac assessment, things like that. Ok. Um So different patients. So a patient with multiple cafe, Ole and how they have a biopsy of a deep le lesion that they've noticed and the histology result comes back and it's positive. S 100 keratin is negative but it says that there's features of malignancy. So anyone have any ideas about what s 100 might mean in a histology report Melanoma, I think. Is that right? No, no, might be related but uh not on, not, not that I'm aware of. Sorry, any thoughts on anyone. So, if we're thinking multiple cafe, Au Lait, I'll say that they're smooth. What condition might you think the patient has? Neurofibromatosis? Yeah, neurofibromatosis. So what kind of lesions might someone with neurofibromatosis get California cafe. I like sports, nice and smooth. So this is a biopsy. Someone with neurofibromatosis has had and it's got features of malignancy. So any anyone know what uh what kind of cancer someone with, er NF might have sarcoma. Uh It is a type of sarcoma. Yeah. So I've not got it in its name though. So uh they are at risk of malignant peripheral nerve sheath tumors. So, um neurofibromatosis patients when they get a painful lesion, it needs to be assessed quite thoroughly. Ok. And um this is a very typical histology report that you might get for them uh probably less likely to come up in the MC QS and we'll go through some of the conditions uh of neurofibromatosis with orthopedics in a minute. But you all know that there's two different types of neurofibromatosis. But if we're looking at uh MP NST, we're predominantly looking at NF 1 4% of patients with NF one will go on to develop um a malignant peripheral nerve sheath tumor. Ok. And they're quite serious because at five years, it's only about a 30% survival rate. Um So this is a, a patient um when I was on fellowship. So you can just see sake from coming into view here back of um ilium and you have like this dumbbell shaped lesion uh coming off of her sciatic nerve as it's coming through the notch. Ok. So it's dumbbells out through the notch and that was a malignant peripheral nerve sheath tumor. Ok. Quite large. This lady had presented about two or three times uh to her local hospital with sciatica, been discharged and eventually on the third time she was scanned and they just picked this up on the periphery of her uh query called a equina scan. Um Yeah, so quite difficult for her because it, it ended up in a delay of diagnosis for her for quite a while. Um probably over about three or four months to get the uh MRI scan. And um she wasn't known to have NF one, but she did have quite a bit of auxiliary freckling and she did have some cafe. And so the whole diagnosis came as, as kind of one package for her. And this is what her operation looked like. Ok. So she's got this question mark incision that goes all the way down to her knee. Ok. And she's having uh a hemipelvectomy. So part of her pelvis, part of her sacrum taken away and this lesion went up her nerve roots onto her spine. So there were spinal surgeons, there were general surgeons, vascular plastics and sarcoma here and this was the tumor that they were excising and it went all the way down um parallel to her hamstring. So quite a significant surgery to have in terms of the resection. But then also obviously the loss of the function of the sciatic nerve. And you can imagine what it's like trying to get this kind of size wound to heal and the dead space management there. Yeah, big surgeries. So type one neurofibromatosis. Um Actually you guys tell me what kind of things do patients get orthopedic or non orthopedic related with NF one, I gave one away spots. Sebastian. Which ones? The nice smooth California, California. Yeah. Anyone remember anything else? Uh leash nodules? Thank you, Tom. What are they? Oh. Uh described by leash. They are a type of nodule. What part of the body? Um skin. Ok. You do your homework while we carry on and let us know when you find out the answer. Any other advances? Anybody I get eye problems? Oh, is that Pinger? It is me. Uh Hello. P what kind of eye problems do they get uh on the optic nerve, um, a tumorous. Um, you and Tom might want to speak to one another. Oh. actually le le nodules on your eyeballs. I uh pardon? 1 to 2 millimeter yellow, brown dome shaped lesions of the iris surface. Uh, that's leash nodules. Yeah. So the, the leash nodules are in the eye as well. If you, um, orthopedic related ones, you get antra lateral bowing of your tibia. Ok. Do they get heavy hypertrophy? Um I don't think, uh, unless they had kind of, I wouldn't say it's like kind of a top differential for a hemihypertrophy. Um Yeah, I was gonna say with the antila bowing and it's usually, I think because of congenital pseudoarthrosis. Is that right? Absolutely. Yeah. So, congenital pseudarthrosis uh with anterolateral bowing uh for NF one. And it's sometimes that there's, um, a lesion at that point as well. So they might be a reason underlying the bowing. Ok. Um Axillary freckling, obviously, the fibromas, you know, the lumps on the skin that they have, I can't remember the number. You'll have to look it, look it up, but there's a kind of set criteria for diagnosing N NF in terms of the number of each of these things that they should have. Um So don't forget the fibroma fibromas in the skin and then associated, obviously MP NST. OK. Fine. Uh If you're unhappy with, um, malignant peripheral nerve sheath tumors, the whole section has to come out with a margin. Ok. So, um, either usually done by sarcoma or joint with plastics and obviously, if you were talking to someone in an exam about it, you'd have to talk about what function that they're going to lose when they have that nerve removed. Ok. And then you might, then for higher order thinking, depending on what nerve it is that's been removed, you might talk about things like, um, tendon transfers in terms of maintaining function. OK? If it was relevant. OK. All right. So this is our next x-ray completely different now. OK. New, new topic moving away from things that are fibrous. Anyone want to take this one? I'm happy to have no one else's, but obviously, yeah, go ahead. OK. So, um this is an ap radiograph of um a hand and the most obvious abnormality is uh multiple um uh lytic lesions uh within the metacarpals um which look fairly expansile but have a narrow zone of transition. Um And these look most likely fitting with the diagnosis of enchondromas. Um uh And because there are multiple enchondromas, you may be suspicious more so of either um Maffucci's or an s um condition good if you had to gamble on this one, pretty, what would you say it is S or Maffucci? Um Oh yes, yeah. Why? Uh because it's affecting more. So the small bones of the hands and um they tend to have the multiple enchondromas um as opposed to, I think you get more association with hemangioma and other things like that, I believe with Maffucci's. Yeah. So the uh AVMs and hemangioma is kind of the important differentiator here. So, er cri was spot on. So we've got multiple bones that are involved with these kind of expansile lytic lesions. Um We've got endosteal scalloping. So here you can see that scalloping pattern, the cortex, cortices are really thinned out, aren't they? There's a couple of deformities that might be starting to um develop as well. Isn't there kind of bowing in some of these uh bones there? Uh Don't forget to say that it's an immature skeleton. Um And yeah, absolutely. Right. So describe the lesion, say, what do you think is consistent with? And then uh if there's an associated syndrome, move on to that. OK. So this is Oier syndrome. So multiple enchondromas. So lots of people get confused between enchondromas and osteochondromas, your enchondromas. N meaning inside chondroma. So you've got cartilage that's formed on the inside of the bone? OK. Enchondroma. So in olia, they do get leg length discrepancies if the growth plates are affected or if there's a significant deformity that leads to a leg length discrepancy. OK. And people can actually have quite severe deformities with this. OK. The malignant transformation is um still present and if you, if you had to hazard a guess that what would they transform into an enchondroma, so they tend to get a chondrocarcinoma. Yeah. So, uh, anything that is cartilage based to begin with, so, either an osteochondroma or an enchondroma is at risk of malignant transformation into a chondrosarcoma. Yeah. In the same way that somebody with a fibrous dysplasia, if they were to have a malignant transformation, it might go from a fibrous dysplasia to a fibrosarcoma. Yeah. Um, and these patients are at fracture risk. So you do occasionally see patients coming in with enchondromas, with pain and you need to get an X ray and probably get an MRI scan to either rule out malignant transformation or a knock fracture on there if you can't see one on their x rays. Ok. So uh histology wise, they don't often show up in the exams because it's just not an awful lot to say other than big B er blue balls, which obviously don't um write in the um histology that it's just, you know, they would just say it's hyaline cartilage, isn't it? But it's these balls of cartilage that you see. So I haven't seen it come up as an M CQ question. Uh So Chris's mentioned two syndromes. So again, we've got another lesion, uh another patient here who's got multiple enchondromas, but the giveaway on this patient is, is that in the soft tissues, there's all these kind of calcific flebilis and these are signs that the patient has got either uh slow kind of low flow, er AVM S or angioma or hemangiomas and that's uh typical of Maffucci syndrome. OK. Maffucci's is a bit more serious than s because their risk of transformation is much, much higher. OK. So it's much less benign and they need close follow up. So I would always, if you're describing an x-ray of an enchondroma mention either a positive or negative finding of calcifications in the soft tissues to suggest um AVM S OK? Because you're just trying to show your higher order thinking of what you're differentiating for that patient. OK. Next condition anyone wants to take this off? Yeah, I can do this one. Can you hear me? Go ahead. Yeah. Yeah, go ahead. Um So this is a uh ap of a uh sleet immature or nearly sleet immature um individual ap of the knee uh showing multiple extraosseous growth from uh around the metaphysis of both the distal femur and the proximal uh tibia. Mhm Yeah. Po growth with a one seem to be uh uh ossific and bony in nature. Uh growing away from the joint um suggestive of uh exostosis and the fact that he's got at least three, probably four, maybe even more might be suggestive of multiple hereditary exostosis. Absolutely perfect. So, what are the key parts on this x-ray? Um in terms of your thinking. So, exostosis is the old man name for now, osteochondromas for anyone that's interested. Um But they are exostosis and it does help you remember that they exit. So they're leaving the bone OK. And if you notice that each of these are growing away from the growth plate. Ok. So it's a key feature of an osteochondroma exostosis. They grow away from the growth plate. And then do you know how it, how it's thought they form? Uh I can't remember, they, they form at the edge of the P cyst there and then the bone grows it, they, they're left behind but continue to grow. So they're sort of a part of the and they continue to grow because the part of the phy cys is left behind or something like that. I can't remember exactly. Yeah. So, uh it's thought that um cartilage based cells from the periphery of the piscis escape. And that's how an osteochondroma forms are pretty similar to the NF situation is, is that once they're there and the leg continues to grow, they appear to move up the dif towards the diy, but it's just that the leg has continued to grow. All right. Um But they still remain in the direction of a way from the phy cyst. What do you think this is? Uh it could be another um uh more of like acr uh osteochondroma. Um So just explain to everyone else what sear osteochondroma means. So there's two types of pedunculation and the cr the pedunculated are the ones that appear to be coming off the bone. So, more like a uh I don't know a piece of something on a on a pedicle, I suppose. Yeah. Whereas the SSR ones are flat and tend to lie um on the cortex of the bone. Yeah. So two different types of osteochondromas. The ones that are stick up on a stalk like this one. OK. And then other ones that will have like a low flat stalk and mainly a cartilage cap. OK. What this might be is that actually this is an exostosis either coming at you or going behind the screen. OK. They do sometimes look a bit odd on an X ray and it might just be that that's uh pedunculated and growing out in the back of the femur. So they might have neurovascular kind of symptoms from one growing backwards. So sometimes things look a little bit odd on the X rays of these and then you get a later and then you realize that actually it's because it was growing, it was either you were end on, on the x-ray. OK. Um So just bear that in mind when you look at these and go, oh, actually, you know what that won't really be rubbing on anything that'll be fine. Actually, that could on the lateral, be quite a significant posterior osteochondroma er good. So it's autosomal dominant inheritance and um when you have multiple hereditary exostosis and it, there's three different gene patterns. Ben can you remember the other two? Uh no, is it XT two and three? Yes, it is. I wasn't being mean I probably so autosomal dominant, all of them are except um three different genes. So E XT 12 and three, if you have a XT one, you're more likely to have more osteochondromas, the more osteochondromas you have, the more likely you are to have deformities or more severe deformities and the more likely you are therefore to have leg discrepancies. All right. Um You also have to remember that if you have a XT one, they're a little bit more likely to transform than if you have um type two or three. OK. But lifetime's transformation risk around, you know, magical orthopedic 5%. OK. The more proximal an osteochondroma is so the closest to the pelvis or the closer to the shoulder, there's slightly more risk of um transformation than say something that's more distal. I can't find a number for you for that though. So this is my very bad sketch of what uh an osteochondroma is. OK. So you have the main bit of the bone, you have the osseous part. So the stalk and then you have this big cartilage cap. OK? And I see people frequently following osteochondromas up by x-ray. But what are you actually interested when you're following up an osteochondroma? Be you're interested in the cartilage cap because of of or of risk of transformation to chondrosarcoma? Yeah. So when you do an X ray, you, you don't see the cartilage cap, right? So it's just something to bear in mind, think of the logics and the, the question that you're actually asking by getting uh certain investigations. Ok. So this is then the cartilage cap. Now, what kind of cartilage caps would you be worried about them? Uh, ones that are growing? Um, so on, on serial imaging or if I was five and I had a cottage cap that was growing, would you be worried? No, but it's so it's, it's growing after skeletal maturity. So you'd expect these to stop growing at skeletal maturity. So it's anything that's growing after speech maturity, um or the size and I can't remember what the cut off of the size is. I want to say five millimeters, but that seems far too small so that it's a bit small. Yeah. Pick a typical orthopedic number a bit like kns into fibrous cortical defects, five centimeters, two centimeters, 5%. No, don't worry. So roughly around the anything thicker than around two centimeters, you'd start to be a bit cautious about. So Ben's right, they should stop growing after skeletal maturity. So if anyone comes in and they've got serial scans or they're saying that their lump is increasing in size um after skeletal maturity, then you would be concerned about that cartilage cap. Likewise, if you did have a child and the cartilage cap was increasing at a greater rate than you would expect for their growth, then that would still be concerning. But you will see that there is some, you know, subtle change as the child grows in size, which not unreasonable. OK. But if it's disproportionate, then that's more concerning. So in terms of which is more worrying and this came up as a part two question a fair while ago. But I think it's an, is actually a nice question to ask someone is um the, the question was going along, it was a multiple hereditary exostosis and then the ending of it was. So, which ones would you actually be worried about? So, just to kind of reiterate and reinforce the more proximal, the more likely they are to transform. If they're deep, they're difficult for the patient to monitor. So they're not gonna be able to tell if they're getting in er increasing in size until it's maybe too late or they start getting symptoms because it's got bigger. So, anything deep. So anything on the pelvis or proximal femur, no one's really gonna be able to monitor it themselves. Are they um a growing cap after skeletal maturity or one that becomes painful? Ok. And getting symptoms of neurovascular compromise because actually, uh yes, the osteochondroma can transform, but actually they can get nerve compression. So, um you have patients um with common perineal uh palsies, for example, are quite common around the knee. Uh I've had someone uh with a posterior rising distal femur that went on to have a pseudoaneurysm in the popliteal fossa. And they can also develop bursitis. Uh particularly if you've got them coming off the medial side of your knee and you get, um, kind of pe bursitis. Ok. Quite common in, um, adolescents that occurring. So, although these might, this might not be a worrying one, but these ones might become quite worrying as well. So just to try and think of how you might answer that question. So, from a cancer point of view, but actually also from a complication of having an osteochondroma and local effects of size. OK. Everyone happy with that side of things. Can everyone remember how to draw a Planet Square for autosomal dominance inheritance? Do you guys want to quickly draw one? And then someone can maybe show the screen and talk through it? Kelly. Yeah. Sorry. Are you waiting for me? Do I need to stop screen sharing for you to share Mike or? Uh no, I'm just uh thinking I've got bone pen and paper. Oh OK. Anyone else as well? You can have multiples of you doing it. I mean, everyone should sit there and draw one. I'll even draw one if I can find a pen. Can everyone remember what a Planet Square is? I guess so. No, Tom looks like his game. Oh my. Oh, my cameras not working. Oh, convenient. Oh uh I think is that upon it square? So they talk us through it. So you've got parent one. I've got the matter on the top. Yeah. And the father on the bottom on the, on the Y. Mhm. So if she has one copy of the gene, yeah, then that, because it's dominant, a child that inherits a copy of that gene will have that syndrome. Yeah. Regardless of what the father has. So what's the chance of that family having a child with? Mh Cocoa? Stop it. Uh chance is 50%. Yeah. Perfect. So in case, I don't know if this comes up any clearer for people. So my right on cue. So pick a letter. OK. Uh One capital is diseased. Little letter is non diseased. OK. So that's mum. So she's uh affected by the disease because it's autosomal dominant and then she has a partner who is does not carry it. So they're both um little lower case, sorry. And so they have a 50% chance that the mum obviously she can only give one or the other countries. So she's got a 50% chance of transmitting it on. OK. So again, really common M CQ questions. Common Basic Science station. Thank you, Mike. Thanks. Uh Can you see my slides still? Yes, but they've gone. Oh yeah, they're up now up now. Perfect. We'll flick through that bit. OK. Lovely. This is a recap from something that we talked about last week. So anyone would like to describe this one. This is the ap of a knee. It shows a lesion in the epiphysis. Um It is with a narrow zone of transformation um there's no associated fractures or periosteal reaction. It's not, it's a sorry, it's abutting the subchondral bone but not eroding into it. Uh So is this a giant cell tumor close? So what would your differential be for a purely epiphyseal based lesion? Um uh II sorry, I can't remember. Ok, don't worry. So um like it's cartilage based this one if that helps uh any anybody wants anyone remember looking at a similar x-ray last week, epiphyseal based lesion it chondroblastomas. Um Yeah, chondroblastoma. Perfect. Um But yeah, Tom II get where you're coming from. It's kind of abutting the articular surface. And so giant cell tumors do behave in that way. They're often metaphyseal and then they abut up against the surface. All right. Um And a bit more aggressive looking, this looks quite benign in itself, doesn't it? Um And obviously because they're purely epi epiphys based, they don't get, they don't really get very big. OK. Whereas the giant cell tumors would probably take up three quarters of that area. OK. Uh Good. So chondroblastomas know anything about them then Mike. No, that's all right. So, all right. So the epiphyseal based lesion, whenever you see a purely epiphyseal based lesion, you probably also want to think about infection just as a differential. OK? They're most common at the knee again, proximal tibial or distal femur. OK. And if you get a CT scan, you'll see lots of calcifications kind of that sting. Look on CT, they don't have a central nidus, like an osteoid osteoma does. Ok. So it's more of a stippling on CT scan. And although they're benign, they're one of these ones that can rarely metastasize to the lung even kind of like 20 odd years down the line. Ok. But it is very rare for it to happen. So, treatment wise for chondroblastomas is usually first line least invasive option is to try something like radiofrequency ablation. OK, done by the radiologist. And if it was either didn't work or it recurred, then you would try something like curettage and grafting uh again, probably with allograft. OK. Um Sometimes people might fill these up with cement, but you just have to be very cautious and remember that actually the heat of the cement could cause some chondral damage if it is up a up and abutting the chondral surface. Ok. So I'd usually pick bone graft in this kind of situation. All right. Uh I think this is probably one of the last bits in the chondral base lesions. But any thoughts on this, this patient uh was toing and froing between GP and general surgeons with constipation and we'll say they are in their kind of late sixties, early seventies. So I think chondrosarcoma looking at this. Yeah, exactly. So big lesion arising off of the pelvis, it's got this kind of stippled uh texture to it where it's not all kind of confluent uh in its color and anyone kind of over the age of, you know, 5060 with pelvic lesion. I would think of chondrosarcoma until proven otherwise, obviously, more common would be a metastasis. Uh, but large lesion like this, that's aggressive, think chondrosarcoma. All right. Uh, and if you ever see someone with a dedifferentiated chondrosarcoma or a histology report with that, it's a very, very poor prognosis for that patient. Ok. Uh, so it's more of a nod to completing um cartilage tumors, I think, rather than anything else. Oh, no one. Last cottage based one. And then you're free of cottage GS. So, er, any thoughts for this one? Very popular M CQ topic? Is it an osteoid osteoma? So it could be an osteoid osteoma. Why do you say that? Uh it looks like it might have a little nidus in the middle? It does look like it's got a little nidus in it. What does nidus mean? Mike? Um small focus. It means um nest. Ok. So osteoid osteoma, it looks a bit like there is an egg in the nest. Yeah. Um So this could be your differential could be an osteoid osteoma, but I'm gonna come back to, when does a hill become a mountain? And so when does an osteoid osteoma become something else? So, I was thinking of possible osteoblastoma and that's just because of the size of it and the fact that it has quite a thin uh a thin cortex around it as opposed to like an osteoid osteoma. Yeah. Perfect. So, uh it's exactly the same process, Mike as an osteoid osteoma, except because of its size. It's now an osteoblastoma. Ok. Uh And osteoblastomas are really co common uh occurrence in the back of the spine. Ok. Uh So, posterior elements, they are about three times more common, I think in boys than they are in, in females. Um, and quite common around adolescents. So, if you have say an 18, early 20 year old who develops back pain, um this would be a reason to uh explore that further. Ok. And yeah, almost half of them are happening in the spine. So um back pain is quite a common symptom of these uh treatment wise. What options do you think you've got? So I think we spoke last week about um touch on osteoid, osteomas and radiofrequency ablation. Do you think it's appropriate here? Probably not with its proximity to the spinal cord? Yeah, perfect. Well done. Tom. So treatment wise uh radiofrequency ablation if it's in the spine is not an option. Ok. So it might be that they undergo curettage and grafting plus minus metalwork if it's required from a structural point of view. Ok. So, er, apologies in advance for my graphic on this. OK. So if we say that this is a bone, there's some form of muscle between the bone and the skin and this is your nidus within your lesion. OK. You put it in a probe and you heat it up and actually the heat that gets expelled from it probably only goes just beyond the bone into the muscle at worst. Ok. And so that would be quite a safe lesion to use it for. But if you have a lesion on the left here, that is actually a subcutaneous bone. So say um the ulnar or the anterior tibia, actually, your heat is probably going to get to the skin and you're at risk of um skin necrosis from inside out because there isn't a lot between the skin and the where the probe is heated up. Ok. Uh My picture on the right is imagining that there's a, a nerve nearby the yellow and then you've got a layer of muscle and a layer of skin. And again, if you put your probe in, yes, you're not gonna get any skin necrosis, but you're gonna risk uh neural uh issues because you might heat the nerve up. Ok. So just think about um radio frequency might be appropriate, but you would speak to the radiologist about whether or not they felt that it was an appropriate area to use it. OK. Um I was just gonna ask, sorry, Kate, if that's OK. Um When I was looking at a few of these questions because initially, I was like, oh if they're within the spine, just avoid radiofrequency. But I think a bit like you were saying that if they're in the vertebral body or not in the posterior structures or not that large, then you can still do ra for them. So kind of, I guess in part one, it's more definitive, but like in part two, I guess you would give, like you said, just say to them that OK, you would look at where it is the size of it and then discuss that with the radiologist, radiofrequency, ablation probe heats up about a centimeter cubed. Um So, um even if I refer someone now, I just, I just drop an email to the interventional radiologist and say, say, is this one that you think that you can ablate? And if so then I'll refer it on kind of thing. Um And yeah, it's just really thinking about the location of it in the bone. So vertebral body might be OK. Um But kind of posterior elements sitting kind of around the pedicle things that they're probably going to be too close to the cord or, you know, nerve nerve roots, things like that. All right. OK. Great. Yeah. But yeah, I think in the to as long as you're explaining, uh you know, ideally, I'd treat this with radiofrequency ablation, but I'm not sure if this lesion is specifically appropriate for it, but I'd have a conversation in through MDT with the radiologist and get their opinion and if not, then I would talk to the patient about curator and grafting. Yeah. Ok. Perfect. Thank you. No worries. Uh everyone happy from that point of view. Oh, ok. One more slide. So size of lesion. So, uh I had a young lady who had got a lesion uh in her ulnar and it was really quite, it was a lot of periostitis, but the actual lesion itself was not very big. Um, but it was one of the ones that I thought, I actually contacted the radiologist and said to them, is this too big to do radio frequency for, are you gonna be able to put enough probes in? Like, is there a limit? Um, but actually they, they were able to, but it is something they take into consideration as to how likely they think it is going to be, uh, treatable with it. So, again, so a big lesion might be another reason to have a chat with, um, radiology before kind of sending them for the procedure. Ok. I think that's my last slide on radio fre constipation. It is. Ok. Uh, shall we take a, do you guys want 1015 minute break tto up? Yeah, 10 minutes, 10 minutes. Ok. Cool. Take a break and then we'll do some bony bits. Ok. Um, maybe everyone's back. Uh, I've dropped two links in the chat. The first one is, uh, the American website that's got, uh, quite, is quite nicely laid out for, uh, quite a lot of different tumors. Er, there's some that they haven't filled out yet but it's overall, it's pretty good. Better than kind of Ortho bullets. Um, my personal opinion. Anyway, uh, the second link takes you to a few different P DFS. But the one that might be of interest is the Sarcoma follow up in the London Sarcoma Service just gives you an idea of kind of how frequently chest surveillance is done for these patients, um, which you don't really need to know for the exam too much, uh, information, but you might be interested if you have someone coming into clinic uh or just in general. OK. And that includes things like the G CT S and things like that as well. Uh Cool or? Ok. Uh So we're kind of moving into a bit of bone now rather than the cartilage and the fibrous ones. Uh Anyone would like to describe this x-ray. Yeah, go ahead and uh so this is ap view of a skeletally immature left femur. Uh It comes in the whole femur, there's lesions in the diaphysis of the femur that uh shows some evidence of periosteal reaction. Yeah. Um The head of the femur doesn't appear to be affected and neither does the distal femur. So it all appears to be in the metaphysis. Um What else do we say? There's a moderate zone of transition? Yeah, I mean, yeah, you can vaguely mark out where it is but it's not, it's not particularly well defined, is it? Yeah. What would you say about the per reaction, Mike Um, well, I wonder if it, it, it looks all looks very fluffy. Yeah. So, would you say that it's kind of like layers or that it's a bit kind of spiky? Is it? Well, I was looking for that but I don't think it is. Is it a sunburst appearance? Oh, yeah. So it's a bit, a bit more kind of sunburst, isn't it? So, you've got these spiculations coming out which you don't see with onion skinning, but there is just a subtle hint that I could would kind of can see where you're thinking onion skin and that it just looks slightly like there might be a layer there. But I think the overwhelming, the majority of this is more that it's kind of and I think that goes with the fluffiness that you're talking about is that, yeah, it's this kind of everything sticking out of the periosteum. So sunburst. Yes. So where might that push you towards? Do you think this is benign or it's malignant? Uh So this looks to have a malignant pattern? Um-hum. And if you had to pick, what do you think it would be uh osteosarcoma? Good. Uh And if it had been onion skin, what might you think, then I'll say Ewing Sarcoma and you'd say Ewing sarcoma perfect. So, um I haven't really gone into any detail on this talk or the last one about the nuances of different sarcomas cos there are so many of them but I think from a kind of spotting point of view, seeing this as more spiculated and sunburst er fits more with an osteosarcoma. If you see something that is very onion, skin layers of periosteal reaction, you're thinking more Ewings. Ok. So you can differentiate on the x-ray between the two. So what are you gonna do for this patient, Mike? How are you gonna work them up? So uh thorough history and examination. Mhm. Uh See if they got any pain in any other. Yeah, pound or elsewhere. Uh As I'm concerned, this is malignant, get a set of baseline bloods, including normal tumor markers and complete some staging. Mhm. And involve a tumor center. Good. How are you gonna stage the patient? What imaging are you going to get the CT chest up pelvis? Mhm. Uh Do you do a skeletal survey for all of these? Uh No. So I'd get an MRI scan of the whole femur that's to look for the extent of the tumor, any soft tissue involvement and then to see if there's any skip metastases within the same bone. So if they say had a a metastasis down here or up in the femoral head. Ok. Um And then as you say tumor referral, the tumor staging, the tumor center will do further staging by means of some form of whole body um staging. So in a tumor center, that's most likely with something like an osteosarcoma going to be a whole body MRI scan. But if you're doing that, say out of a tumor center, you might be getting a nuclear medicine, bone scan to look for any other lesions. Ok. So local staging, systemic staging and bloods. Uh And you've done your referral to the tumor unit and they obviously want to get a biopsy. So, er, anybody else give Mike a breaker principles of biopsy? I know we went through them last time, but I just thought a bit of recap and reinforcement is always useful. So all the principles of tumor biopsy. Got it. Um So you want to show it's done at uh appropriate place by an appropriate uh person as planned preoperatively by the uh operating surgeon in center. Um We want to ensure it's an adequate uh sample. So that that would involve what type of imaging uh you're going to use. So, whether it's CT, if it's bone lesion or ultrasound, if it's soft tissue lesion and getting a representative sample of this, the tumor, which may be um uh avoiding the center, which might be necrotic. Uh And if possible to get a soft tissue sample because that will give you a quicker diagnosis. Um um You want to prevent any seeding of the uh tumor. Uh So when you're taking a sample to invade one compartment only, not uh going across any neurovascular bundles, ensuring appropriate hemostasis. Uh If you're doing an open biopsies, ensuring good hemostasis throughout, uh usually if you're gonna use a drain to put it in line, either coming out of the wound or in line with the wound. Um And uh again, your incision site is gonna be uh as planned for further surgery. Um Biopsy tract is tattooed for possible excision at a later date. Um uh And then it's appropriately analyzed uh at a specialist tumor center, uh histopathology with uh genotyping. Perfect. So, really nice answer. Ben nice and clear and I think you structured it nicely because you kind of took each in each section, didn't you rather kind of going back and forth of just listing them randomly? So you want something that is going to be representative and you need some form of imaging, you need an MD discussion to make sure that that is coming from a representative area, but it's also going to come through an approach that's extensile and going to be in line with the definitive treatment that's going to take place. And then you talked about the components of it of reducing the risk of seeding. So one compartment shortest approach invade the least number of muscles, avoid the neurovascular bundle and then hemostasis point of view, avoiding any hematoma that will contaminate a greater area of tissue. OK. So nice answer, Ben. Well done. OK. Can I just ask a very quick question again? Um So you know, we were talking about the primary work up for these patients. So I was listening to a talk by um somebody who was talking about kind of bone tumors and they were saying for these ones that have, you know, kind of pathogenic features suggesting maybe osteosarcoma um in kids. Um Is there an argument to not do a CT chest Abdel and just get a chest X ray for radiation purposes or would you say that still you should get a CT chest? So if I think someone's got a sarcoma and I am looking, if they have got sarcoma met, then I'm only going to get a CT chest. Ok. Because these don't metastasize. There are a couple that, that do, but they're very rare that I would get a CT chest if I am doing staging of somebody who has got a lesion in their femur because, and they're say over 40 they most likely got metastatic disease, then I'm doing a CT chest Abels to look for a primary solid tumor and to confirm that this is metastasis. But likewise, if it turned out that it was a primary brain tumor, I've got my CT chest for perfect. So for these ones, I could just say CT chest because of the fact that we know that they predominant, I wouldn't rely on a chest X ray of somebody with at the point of diagnosis. Once they've had a CT chest, then if there's nothing on it or there is something on it, then they go to chest X ray surveillance. OK. But they should have a staging ct to begin with because you can get really kind of small kind of five millimeters or so nodules or indeterminate nodules that they'll then maybe have an interval ct chest done to see if it's increasing in size fine. But you could say that we just did a CT chest because we know that there's a very small chance for this kind of younger age group that they would metastasize elsewhere. Yeah. Absolutely. OK. Um Yeah. So mostly sarcomas generally go to the chest. We mentioned last week that some go to the lymph nodes. Uh and that's a really common uh M CQ question. But I, yeah, for staging from a metastasis point of view of sarcoma CT chest from the point of view of work up for is this bone lesion a metastasis? And I'm looking for a solid organ tumor then ct chest, a pelvis. OK. Thank you. No worries. Um OK. So be you've done the biopsy, it comes back, it confirms an osteosarcoma and uh they wanna talk about um surgical options. What goes through your mind? There's no big soft tissue component. The neurovascular bundle is not infected Ben, Ben. 00 Mike or anyone. So uh jump in bent when I'm dry up. Uh So enblock resection with uh some uh additional chemotherapy. Mhm um Options, I guess proximal femoral, replace, well, proximal femoral replacements, unlikely to be enough. Mhm So maybe a customized femoral uh implant Mhm. Uh, issues. They're skeletally immature. So they're going to continue growing from the knee. Yeah. Um, what, pardon? Why is that of interest? Uh. Mm. It's a good point. It's something to consider you. You want to plan for a leg length discrepancy, don't you? Or to avoid it if it's relevant. So, if they were, say 1314 and they weren't going to grow very much, you probably would be less inclined. But if this is an eight year old, then that's quite a significant leg discrepancy that they'll develop, isn't it? So it's a higher order thinking part of the station if you're pushing for a seven or an eight. So globally speaking, if someone's got a sarcoma, the first question is, is this, is this resectable? OK. So if you've got tumor that's wrapped around or involving a nerve, then the likelihood that you're gonna be able to resect it with adequate Margi margin to avoid recurrence or persistent disease is pretty slim, isn't it? So then, you know, automatically if it's not resectable, you're probably gonna be going down the road of talking about amputation. Yep, if the neurovascular bundle is not involved and uh you're going to be able to resect it, then your next question is, can I reconstruct it because if you can resect it, but you can't reconstruct it, then again, you're probably going down the route of amputation, aren't you? But if it's resectable and you can reconstruct it, then you're going down the route of limb salvage. So, with this patient, we've already said uh the nerves not involved, we've said that there's not a big soft tissue component. So it is resectable. Ok. So the question is, is it reconstructable? And uh Mike's quite rightly pointed out that a proximal femoral replacement, you can do custom made ones that are really long. Ok. But you've got to think about, you can't have a really a stem that's gonna go through the growth plate. And you've got to think about the fact that this leg is still going to continue to grow. So your higher order thinking then further goes down the route of managing leg length discrepancy in pediatric tumors. OK. So, er, this, er, young girl went on to have a sub total femoral replacement and it was custom made and you can see here that she's got two screws in it. Now it's a slightly older generation. So it is telescoping, but it requires a procedure to loosen the screws off to telescopes. So that as she grows, you can grow the implant. But now the more modern ones have got a magnet in and you literally put a magnet over the top and you can gradually lengthen them. Uh, and they have that done frequently by the physios. OK. And you can see that they've left her growth plate uh untouched. OK. Uh Any questions about that side of things. So high order thinking is it resectable and therefore, is it or is it not salvage? And then can it be reconstructed? Yes or no? OK. Um Just quickly, what do you, what are the margins that um that you would need like? So I'm thinking about whether for example, that GT you could salvage the screw on the top of that. So in terms of margins, so you can see x-ray disease up to here. So they'll then on the MRI scan be a level of reactive disease around it. And then they usually plan for a two centimeter transection point. So we would be like down here plus the two centimeters of wherever the disease was most distal on the MRI scan. Uh And sometimes it's difficult to differentiate between just edema and tumor. And obviously, the sarcoma radiologists are pretty good at doing that. Um So that they minimize the resection as much as possible, but sometimes if they're not sure, then they'll obviously include the edema plus margin. Ok. Uh So for this one, for quite an aggressive osteosarcoma, the GT hasn't been, hasn't been salvaged. Ok. Uh And it, you can see that that plus a bit of edema plus your two centimeters, you're probably not going to be able to keep it. But if there is ever an option, so say in a meta metastatic disease, um I will always try and keep uh some of the GT to reattach it onto the implant. The more modern P fr S now actually have got H A coated GT sections to try and get the bone to grow onto it as well as the screw fixation. And so there's a lot more, I would say that the P FRS that we're using now are a lot more advanced than the kind of the first generation that initially came out for tumors. Um So things like H coated endosteal collars that come down inside of the femur that give you much better rotational stability early on. Um So yeah, they've definitely changed a lot if you wanted to, I'll put some links in later into the chat of the opex for the PFR that I'm using now and I'll see if I can find one of the older ones. You had to see the difference in the implants and used to get with say like the initial striker Mets, which was kind of an early generation uh P FR they had a collar on them that had got a roughish coating and you would get bone growing up onto it. But now if you look at um say Adler P fr it's actually a collar that goes down inside of the bone to get spot welding. Um So yeah, they're making quite a lot of advances with these, these ones are all kind of custom made. So obviously, they don't come with any NJ R data or anything like that. And endoprosthetic haven't started being reported yet in NJ R although it is coming. Any other questions about this one? What, what's the head made of? Uh it's such a bipolar head. This is, yeah. So she'll come back. She will be obviously going back at some point, won't she? She's a, a young patient. So when this becomes a problem and loosens, then she's probably gonna be in um total femur territory at some point, isn't she? Which will involve a hinged knee and she'll obviously have acetabular reconstructions as time goes on. You're always trying to preserve bone for the next procedure a bit like any kind of revision hip procedure. You're always trying to preserve bone for what you're gonna have to potentially do next later down the line. Exactly the same from a tumor point of view. Thanks. No worries. Ok. I'm gonna move on. Uh Mister Pinger. Would you like to complete your uh periostal reaction descriptions or would you like to phone a friend? Well, this looks like it's got classic onion skin appearance of this skeletally immature. Ap Yeah. So you, you can see that these are like layers that are stuck onto the bone almost, aren't they? Yeah. So quite different from the kind of spiky appearance of the one before if we look at that one. Yeah. Yeah, I see. So this one would be, are you in sarcoma? Sarcoma? Good. Uh Fine. Ok. Um I'll leave the, the bone sarcomas to one side. Anyone like to describe this. So, new topic. New lesion. Any thoughts, you can just describe it, you don't have to get a diagnosis. So it's a later of uh the hind foot of a scally immature patient or hind foot and ankle um shows a lesion in the calcaneus uh of the patient. It appears to be uh possible, multiple small cystic or lytic type lesions might possibly be one lesion with loculations, but it looks more like discrete lesions that are um quite oh actually even they look like to be discrete lesions, but even within those discrete lesions, um they are quite well defined. There is an Arizona transition through the uh throughout the the different lesions. Um So there's no obvious periosteal reaction, no obvious soft tissue uh component either on the X ray but further imaging. Ok. Good. Do you think it's benign or cancer? I think it's probably benign, probably benign. Yeah. Any thoughts now or I wonder whether I'm not, I don't know, it looks, looks like it could be something like an like multiple aneurysmal bone cysts or, or one large aneurysmal bone cyst. It's not seen it in the calcaneus. But yeah. No, it's, it is unusual. I did. Yeah, it is unusual in the calcaneum, but you're right, it's an aneurysmal bone cyst. So what investigations would you do for this patient to confirm that? Uh So I'd get a uh an MRI scan of, of the even without a radiology report. How would you know, it was an aneurysmal bone cyst on the MRI scan. So you'd look at um uh there'd be a fluid level on, on the MRI scan. So gas fluid level or? Yeah. Good. Yeah. Yeah. So you, you see fluid levels um within the cysts. So normally you would see fluid levels, wouldn't you uh horizontal? So obviously you have to remember that the patient is lying down. So these are horizontal fluid levels still. Ok. And it's all kind of contained within the calcaneum, it hasn't broken through. And so this is very typical MRI scan of an aneurysmal bone cyst. They are as ben pointed out, not particularly common in the calcaneum though it was a slight trick. Um So most common in the distal femur and the proximal tibia, they're usually intramedullary and they're usually metaphys, OK. Anywhere from the age of 10 to kind of uh mid thirties. And patients usually present with pain and they might have a bit of swelling if the bones say a bit. Um they might have some bony expansion with it. We've said the fluid levels on MRI scan is kind of a giveaway for us and kind of pathognomonic. If you see it on an MRI scan, if you're given one in the exam, they are as Ben said, already benign, but they're locally aggressive. OK? And by the nature of them, it is a bone, it is a cyst that causes bone destruction. You, I mentioned last week that you can get secondary changes that are aneurysmal. Ok. So you might have a giant cell tumor that's been there for a long time and they get secondary aneurysmal bone cyst changes. Ok. So you might start seeing some fluid levels in something that was solid. Uh If you curette them and graft them, there's about a 20% recurrence rate. So reasonable, isn't it like one in five people having it done will have a recurrence. OK. So, treatment options are pretty much if it's, if it's painful, causing problems, it's curettage and grafting. Um And there's not really an awful lot else that you can do about them. OK? If it was something that was recurrent and causing more problems, then you could probably look at things like en bloc resections and reconstruction for that calcaneum. You haven't really got very many options. Have you other than curet and graft? OK. Um There, otherwise it is a pretty straightforward um question if you get them, it's just making that link that it's an aneurysmal bone cyst. OK. Uh So just flick back on our way. Just remember the fluid levels on the MRI scan. OK. Too many things to click through. Can you use a? Yes, you can. But if something is big enough that it's becoming painful, they're probably not going to get enough autograph to fill it. So they take quite a lot of bone to pack in. OK. But it's not, yeah, it's not something that like fibrous dysplasia or it will turn it into it. Um, but it's just the, the volume that you'll need to pack it in. Yeah. Ok. Cause big problems somewhere else. Yeah, exactly. There's only so much of your iliac crest you could probably give up. Uh, cool. Um, any other questions about ABC S? No, uh, anyone other than perhaps Tom, because I think Tom described a similar one last week would like to describe this one. Um Yeah, go ahead. Uh So this shows a um ap radiograph of a proximal humerus. Um There is a lytic lesion uh within the metaphyses uh with a fallen leaf sign um which would be most suggestive of a uh unicameral bone cyst with a possible pathological fracture going through it. Yeah, perfect. So, immature skeleton not, it's not affecting um what's left of the growth, immature skeleton. Um It's not affecting uh the growth plate. It hasn't breached it by the looks of things, but absolutely picked up on the fact that there is a fracture coming through here and this is the fallen leaf sign. So I put this in because I think last week's one um Tom picked it up, but it wasn't a great fallen leaf sign. Whereas this one kind of shows you quite clearly, doesn't it? So part of the cortex has fallen into the cyst. OK. So that's the fallen leaf sign. Uh What do you know about um UBC S then pretty um So there are a benign lesion. Um The management depends very much on the weight bearing status of the limb that, that it involve often. Uh So, in proximal humerus, for example, um you can leave them alone. Um and a lot of the time they will calcify and um the fracture will heal. Um However, you keep them under observation. Uh in case, that wasn't the case if, for example, this was in the proximal femur um because it is a weight bearing um uh uh bone, you'd be more kind of inclined with a fracture to look at treating it. Um And that may require you to obviously uh fill the defect with bone graft, for example, and then obviously fix the fracture. Um Yeah. Good, good. Yeah. Key point here is that the upper limb ones often heal by themselves. OK. Um So with conservative management and actually sometimes after they fracture, um people say sometimes they, they then fill in as well. Um I don't know how true that is really. But yeah, sometimes like years down the line, you then don't see that this, you can see that the cyst is gone. I have seen a couple of those in patients, but whether it happens every time I'm not sure. Um There was a quite a while ago. Um I don't know what you would say. I guess it was in fashion to inject these with me. Oh Yeah. Yeah, I saw that. Yeah, but it, it is a bit historic now and II don't know any centers that still do that. Um But again, it might be something that someone says, oh, so have you heard of any other ways of treating these in uh part two uh of which you can say, you know, historically, these were injected with metal pred, but there isn't any evidence that I'm aware of that this actually encourages healing of the f. Is that right? So that's what that healed. You can then treat the actual aneurysm, not sorry, the UVC with or if it was one that hadn't fractured. So, yeah. Yeah. So you could give a nod to it if you were pushed for further treatment options that you know, they're kind of getting at, but it's not normal treatment now. So a bit like when you have a do P and they bring up using the, I'm going to forget what it's called. Now, the collagenase hands when they talk about injecting with the collagenase plan, is it? But it still comes up in the part two as like treatment options to be aware of. So just on the off chance that they mention it, people used to stick steroids into these, it didn't work. OK, perfect. Thanks. Uh Cool. Uh So moving on to fatty things. So lipomas, the histology is not very exciting. OK? You're not going to get a histology report um on them. There's different types of lipomas. So superficial ones, you might have multiple of them. And then if you have multiple superficial lipomas that's called DERMS disease, er, you will probably, whether you've realized it or not met someone or know someone who's got it. Uh, it is much more common than people realize. Um, and the superficial ones are really super benign. Um, it is incredibly unlikely that they will ever transform into anything other than staying as a fatty lipoma. Ok. You then get lipomas that are within muscles. So they're deep or very rarely, they can be within bone. The ones that are below the level of the fascia are obviously a bit harder for patients to monitor in terms of increasing size. But also they are slightly higher risk that they might transform into a liposarcoma. OK. So just to bear that in mind, you can also get synovial lipomas and um obviously liposarcoma uh as a presentation as well. So, they would be my kind of global headlines of things you should know about lipomas in terms of the different sites that they can be. And we're just gonna go through some different pictures of different types of lipomas. OK. So, uh anyone want to describe this picture or pictures? OK. I've kind of given you the answer already. Do we think that's normal appearance of the Synovium? No, no, thank you. Um So uh it's amri scan of a of a knee, there's two axial slices of T one and at two And then the sagittal slice is at two weighted image. Um It shows uh growth within the synovium and the joint itself, the bones don't appear to be infected and it doesn't appear to extend outside of the joint capsule. Um There's uh areas of low intensity on the T two. So, so small areas of low intensity on the T two images surrounded by the normal synovial fluid. Um And uh yeah, I don't know how to describe it, but I imagine it's PV NS. So this is actually a sinovial lipoma, but it does look quite similar to PVN. So definitely it was referred as P VN. Um And whenever you see this kind of picture of a some form of sinovial hypertrophy, it would be worth in the exam talking about where in the joints involved. So this is predominantly uh anterior knee, isn't it? Patellofemoral joint seems to um predominantly be involved. But there is a hint on the sagittata that there is some disease at the back of the knee. So why would that be relevant then whether that was PVNS or just like uh neurovascular bundle the back of the knee. So whether any growth there is causing any neurovascular compromise. Yeah. So any neurovascular symptoms, how are you going to, if it's going to be more difficult to access access? Exactly. So um for everyone else, then what is PVNS? Because we haven't covered that? Uh pigmented villonodular synovitis. Yeah. So it's Yeah, it's just a uh uh it's basically like excessive growth of the, um, of the synovium abnormal and they can bleed. So sometimes patients get uh painful hemarthrosis, um, if they've got PVNS and it can affect obviously the entire lining of the joint. So you can get anterior and posterior disease. There's different type, two different types, I would say of PVNS. One where it's just a nodule that's formed and one where it's diffuse where a bit like this kind of feature where it's like the whole joint that's involved with it. OK. If you just have one area that's a nodule, say by the P FJ, that's relatively easy to open and remove. Whereas if you've got this diffuse disease, like this one, you might even be thinking about doing front and back approaches as kind of a staged procedure to excise it for them. Um The astute of you, there will have picked up on the fact that I said, oh, for a nodular one at the front that I would open it to excise it. So if it was just a nodule, why would I not want to put a camera in and do it as an arthroscopic procedures? Is it just in case of malignancy? So like our biopsy sort of principles that if you're then going through the joint, you might accidentally seed some malignancy into the joint. Yeah. So what happens when you put your camera in? What's the next, you put your camera in, you do your an interlateral portal, you put your camera in. What's the next thing you do? What do you turn on water? Hm. And so if that was a tumor and I started shaving it away, where else is that tumor going and around the whole knee, around the whole knee? Right? Because that fluid is going to circulate around the whole knee. So potentially if it was a malignant diagnosis or even PV NS, um I've seeded it all around the knee, haven't I? And what was a simple nodule into potentially diffuse PVNS in the future? Or seeded a tumor all the way around the knee, including two po skin portals. Uh And there are people that have had sarcomas that have had arthroscopic debridements uh of PV NS that have turned out to be sarcomas and ended up with amputations because of uh contamination. So, mini open procedures for removal of the nodule safer. OK. Uh So this example is a synovial lipoma. You don't have to do anything but this patient had quite significant patellofemoral joint symptoms, which is not difficult to imagine is it there's a good level of padding behind it. So, um the posterior disease was not symptomatic. So that was left and they just had an anterior approach to the knee excision. Uh Sino sino sin sinusectomy. Can't get my words out today. All right. Uh OK. What about this one? Any takers you wanna do this one quick. Um Yeah. Ok. Um So I'm just looking at a um MRI scan showing an axial and a sagittal um projection. Um looks like this looking at this, it looks like there is a well demarcated lesion uh within uh the musculature suggesting a potential uh intramuscular lipoma good. Um Yeah. What symptoms do you think this patient came to clinic with? Uh So they may not notice swelling of the compartment itself. Uh They may have pain resulting from that. Um They may notice um creased tightness um may even have restricted range of movement because the muscles may not be contracting um through concentric or eccentric contraction. Normally, I'd guess because of the mass. Uh Yeah. So it could most likely, I guess it would be increased intra compartmental pressure. So like a compartment syndrome like picture. Yeah. So um they weren't too significant. Uh They didn't have significant pain but you mentioned pressure. What other kind of pressure might be there? Pressure on uh pressure on neurovascular structures as well. Um What else? Um this patient presented with a pin palsy? Ok. Fine. Ok. Um And that was um local pressure effect. Sorry, I should have said what joint we were looking at as well because I obvious, isn't it? Um So yeah, so they, they actually presented to their GP with a pin palsy and was found to have. Oh yeah, because you can see it's kind of right next to the radius. Yeah. There, isn't it? Yeah. So um quite interesting. So, um obviously, well, maybe not, obviously, but what, what would you do for them if they've got um nerve symptoms from a lipoma like this? Ok. So, ideally because they've got nerve symptoms, you're looking at someone who's ap two kind of a fairly urgent case, although it's not um metastatic disease. Um You would look at uh obviously getting imaging which we have and then uh planning to excise the lesion for them. Um You would uh hope that this was more of a neuropraxia like picture because of compression. Um So yeah, I would do this through an open approach. Um an approach that I'm more familiar with and something that would allow access. So maybe a Cocker approach, for example. Um but again, you'd have to check that you'd be able to access it adequately. Yeah, you probably need a bit more of the MRI scan to kind of, yeah, decide to do that anyway. But um so this um so this, he still had a biopsy first to prove that it was uh not a liposarcoma. Oh OK. So because then you'd have to take out a lot more, I guess. Yeah. Well, also then is it resectable because it's um obviously very close to the nerve, if not involving the nerve. So, um yeah, so biopsy first exclude the liposarcoma, but then um he's got nerve symptoms. So it would be entirely reasonable. Wouldn't it to remove it. These are not easy when they're in this area. Um And you end up trying to chase them down um between the bones and the forearm as well. The recurrence rate is quite high. Can you get away with um marginal resections for liposarcomas? Because I did read about this and someone was saying that you don't have to do, you know your wide local excisions for them and you can get away with kind of marginal. Is that not? II probably wouldn't risk talking about that from in the part two because I think that would probably be controversial. And the people that are examining, you would probably go down the route of this is you want clear margins. Um I think that that would be quite a nuanced conversation at an MDT with the results of something coming back, perhaps that is marginal resection and then saying this is or isn't worth going back to get a better margin for depending on where the lesion was fine. I think most sarcoma surgeons would go in trying to get a margin on any sarcoma that they're removing just for to reduce the risk of recurrence. It's a balance, isn't it? Of how much tissue you take and affecting function versus survival? So, yes, OK. Fine. Thank you. But I think for part two stay non controversial. I just remember that the people examining you aren't necessarily that subspecialty. So anything that's controversial, they may not be up to date or have not up necessarily up to date but have like the really nuanced kind of any research that's going on behind it, the scenes kind of thing. Fine. OK. Thank you. No worries. Yeah, I guess what we're trying to say is don't dig yourself at home. Uh OK, this patient came in with a painful lump on the medial side of their knee. Uh So this is the ap and lateral view of the knee of a skeletally mature individual. I can see that there's a soft tissue swelling, er the medial joint line on the AP and perhaps on the lateral, you can see a sort of fullness in the posterior aspect. Um So I'd wanna get an MRI scan to uh to, to diagnose what this is and then uh possibly a biopsy. Yeah. So um the bone itself looks OK though, doesn't it, you can just see there's kind of an irregularity in the soft tissue at the side. So they have an MRI scan and it comes back like this. What are your thoughts? Uh So there is a lesion, it looks to be um um it's not sort of uniform um appearance. Um It, I think it looks like it's arising from the um from the ligament um or uh or possibly from um from a tendon sheath. Mm. So it's within the fat layer and I think uh perhaps if we flick back and we look at uh this MRI scan, you know, it's fat because it's the same color as the fat in the subcutaneous tissues. Right? When we look at this 10, the fat, it doesn't fat suppress. Like up here the fat is now black, it doesn't fat suppress. So there is something going on within that uh lesion within the fat layer. So if you had to pick, uh Tom, would you say that this is benign or cancer? Cancer? Again, you've kind of got that poor definition between normal and abnormal, haven't you? You've got mixed features within it. It's not fat suppressing like a lipoma usually would. And this was a liposarcoma on biopsy. OK. So the same principles as all of the other work up in terms of your staging your biopsy. Uh but you've kind of already touched on it. The excision in this area is a little bit tricky, isn't it? Because it's so close to uh M CL? Yeah. Yeah. So, um yeah, this wasn't one of my patients. So I don't actually know what they did for them in the end. But yeah, your higher order thinking if you got this in your part two would start talking about if I excise this actually what's going to happen to the stability of the knee and what am I going to do about it? Ok. Good. Well done, Tom. OK. So uh this patient presents with a painful swelling. Um What do you think about this MRI scan? Anyone it's got a very helpful, a little arrow on it. Anyone else coming up to the exam that's signed in cos I can't see the list of people. It doesn't matter what the body part is. Um, so there's a lesion, it appears to be within the, uh, within the muscle. It's got quite a uniform appearance on the MRI scan, but it's saturating differently to the fat and to the muscle. Um, it's got quite a narrow zone of transition. Um There's an arrow at something that is not the lesion down here. So why is an arrow to this? What's this? Um And maybe there's another kind of area or something coming out of it the other side as well. Is it enough? Yeah, it's enough. So what might this lesion be a nerve related tumor? Like a Schwannoma? Yeah, perfect. So you should on a Schwannoma on one of the views of the MRI scan, be able to see the nerve coming into it and the nerve exiting. Yeah. And that's kind of gives you, that's your, you know, take home of this uh is a Schwannoma in your exam. OK. So uh imaging signs. So one is that uh something entering and something exiting? Um Oh, it's on my next slide. OK. Uh We're gonna talk in a minute about target sign as well, which is often a typical uh sign of schwannomas as well. You're differential in this area might be something like a malignant peripheral nerve sheath tumor. So your, both your benign and your malignant version of, of the lesion and histology wise, we talked about S 100 earlier. OK. So, um in terms of Chordomas, we have a string sign which is the entrance and exit. OK. And we have target sign. So within the lesion, there's an area that has a slightly different signal in the center. Uh And I'm gonna leave it with you with your homework because it comes up as an N CQ question, the difference between what Antoni A and Antoni B is. OK. Um But this is a very typical Schwannoma. Um You'll remember the MP NST that we looked at uh earlier and that had that dumb bowel lesion again, very common uh sign of uh nerve based tumors. OK. Most of the time, a Schwannoma is quite small, they're less than five centimeters. You do get something called an ancient Schwannoma, which has been there for quite a while. And actually these can be a reasonable size. But the moment you get over five centimeters, obviously, your concern would be whether or not it's a malignant peripheral nerve sheath tumor. OK. Everyone happy from that point of view. So if I was shoma, how do you remove them? Do you just chop them out? You want to shell out the uh yeah, the Schwannoma from the rest of the nerve. Yeah. So the the tumor is centric to the nerve and obviously, you can't just go in and, uh, just chop the lesion out. So you have to shell the nerve out. They are often, um, in the Sarcoma units might be done by plastics or PN I, uh, or if they're just straightforward ones done by the Sarcoma team. Ok. Do you mind just flicking back to the slide before I didn't see the target thing. It's quite difficult on the laptop. It, I don't know if you can just make out this, just something subtly different there. That's what it sounds like. I can see it on the right of the screen. Maybe the start of one. Yeah. Yeah. Ok, thanks. Thank you. All right. No worries. I think guys that was all I kind of put in for this afternoon. Anyone want to go through anything or any questions about either today or last week? Ok. It, no questions, anything anyone wants to go to Venom. Um Nick. Um There was one apologies if you've, you've covered it, but um do do, how often do biopsies get done within tumor units? I'm sure I've been told in trauma meetings that they get done at the tumor unit, but whether that caseload would be manageable, I don't know. So, um Stanmore do an awful lot of biopsy. So, um, they Stanmore, um let me stop recording because this bit doesn't actually, why won't it won't let me stop recording anyway. Um