This man presented with a single hyperkeratotic lesion on his upper leg. The lesion was erythematous with some brown-black foci. There was a clinical concern for melanoma. Angiokeratomas often are mistaken for a melanocytic lesion due to their color. This particular lesion was traumatized, leading to its atypical features. Angiokeratomas may occur in isolated or may be multiple or associated with syndromes. The histology is characteristic in this case, with a vascular proliferation in the superficial dermis. There is overlying epidermal hyperplasia. Most lesions are superficial but some lesions may have a deeper component.
There is a vascular lesion in the superficial dermis. The vessels are thin-walled and have size variability.The endothelial lining is bland. The overlying epidermis is acanthotic and papillomatous.