This 43-year-old man presented with several erythematous papules on his penis. The clinician was concerned for bowenoid papulosis. While consistent with bowenoid papulosis, this is not something we diagnose on histology, as the findings are identical to other forms of squamous cell carcinoma in situ. We sign these out as "full-thickness dysplasia". In this case, there was an incidental finding of amyloid, possibly representing macular or lichen amyloidosis. There was no clinical evidence for systemic amyloidosis. This amyloid material stained with Congo Red and keratin immunohistochemical stains. The etiology is unknown, but likely due to chronic irritation.
Description
Histologic sections of skin show an epidermal lesion. Keratinocytes show crowding, nuclear pleomorphism, and several mitoses are present. In the subjacent dermis, in association with a eccrine duct, there is accumulation of acellular grayish amorphous material in globules.
