[A man with an ulcer on his penis].

A 51-year-old male presented with a painful ulcer on his glans penis. Histopathological and radiological examination showed extensive microangiopathy and calcification of small and medium-sized arteries and the diagnosis 'calciphylaxis cutis' was made. Calciphylaxis cutis is caused by calcium deposits in small and medium-sized arteries, and most commonly seen in patients with end-stage renal failure and hyperparathyroidism.