Pseudomelanosis duodeni: a case report with electron-probe X-ray analysis.

Pseudomelanosis of the duodenum is rare. Only 17 cases have been documented in the world literature. A 59-year-old man presented to Bankstown Hospital, New South Wales with dysphagia. On endoscopy, he was found to have melanosis of the duodenum in addition to oesophageal ulceration. It has been previously suggested that the pigment ferrous sulphide is derived from gastro-intestinal bleeding and lodged in the macrophages. A detailed examination of the pigment, including X-ray probe micro-analysis at various levels of the intestinal epithelium as well as in macrophages is presented.