Case report

A 67 year old man was referred to the dermatology department with a two year history of skin lesions on his right leg. The patient was otherwise healthy and not taking any drugs. On physical examination he had painless subcutaneous nodules on the distal part of the right thigh (fig 1⇓) and an asymptomatic eroded, scabbed, violaceous, well defined plaque on the upper side of the right ankle (fig 2]⇓). He had no signs of infection, arterial or venous disease, or history of trauma. Possible diagnoses included lupus vulgaris or other mycobacterioses, necrobiosis, and sarcoidosis. Biopsy specimens were taken from both lesions in the operating theatre under standard aseptic conditions. The patient was told to care for the wounds by daily washing with water …