Clinical presentation

A 67-year-old Caucasian male presented with persistent diarrhoea, weight loss of 15 kg in 3 months, and onychodystrophy. Family history is negative for colon carcinoma. He worked in oil trading and had extensive exposure to sulfuric acid, ammonia and gum resin. Physical examination revealed a vaguely palpable mass and tenderness in the left lower abdominal quadrant. Onycholysis of the fingernails (figure 1) and toenails, alopecia (figure 2) and hyperpigmentation of the skin were noted. CT demonstrated two circular thickenings in the sigmoid and colon ascendens. …