A 43-year-old patient with a 2-year history of orogenital ulceration and hypochromic anaemia developed rapid loss of weight over a period of a few months and presented with a mass in the right iliac fossa, suggestive, clinically and radiologically, of a carcinoma of the caecum. The mass was removed by standard right hemicolectomy. Examination of the resected specimen revealed a large, irregular, ulcerated area of the caecum measuring 7 cm in diameter extending through all the layers of the intestinal wall. Histology showed a non-specific inflammatory infiltrate. One large artery in the pericolic tissue was occluded by organizing thrombus. Five years after the operation, he developed epileptiform seizures. CT scan showed a small infarct in the left insular area of the brain. Six months later he was admitted to another hospital with profuse diarrhoea and died within 24 h from cardiac arrest.