Although this is the most common skin cancer, it often presents as a pearly nodule with telangiectasia, which does not match this patient's presentation.

It frequently presents with a red, scaling, and crusting lesion, or as an ulcer, rather than a pigmented mass.

This woman's 3 cm, brown-black, irregularly bordered, non-symmetrical lesion that has evolved over a few months is suggestive of malignant melanoma. The ABCDE guidelines can help distinguish melanoma from other skin neoplasms. These symptoms fit each of the aspects of the mnemonic: (A)symmetry, (B)order irregularity, (C)olor variation, and (D)iameter >6mm, and (E)volution.

This is a slow-growing fibrohistiocytic tumor that presents as a firm, raised nodule that is flesh-colored to slightly pink or reddish, rather than a pigmented lesion.