A crusted lesion on the penis

Abstract

A 54-year-old white man presented with a 2-year history of an irregular crusted keratotic patch in the midline of the proximal dorsal penile shaft (Fig. 1). This lesion caused him some mild discomfort, but was otherwise asymptomatic. He described a similar lesion occurring at the same site 20 years previously, which had been successfully treated with cautery. No formal diagnosis was made at the time and pertinent histopathology results could not be traced. There was no significant mucocutaneous disease elsewhere and the patient had no family or past medical history of relevance. Histological findingsOn histopathological examination, there was superficial erosion as a result of intraepidermal acantholysis. In the underlying dermis, there was an inflammatory infiltrate of lymphocytes, histiocytes and plasma cells, along with scarring ( Fig. 2a,b). Immunofluorescence studies were negative.What is your diagnosis? (a) (b) Figure 2 (a) Epidermis with features of intraepidermal acantholysis and a mixed lymphoplasmacytic infiltrate in the dermis (haematoxylin and eosin, original magnification 9 100); (b) intraepidermal acantholysis (original magnification 9 400).Figure 1 Irregular crusted keratotic patch in the midline of the proximal dorsal penile shaft. ª 2013 British Association of Dermatologists