Benign mesothelioma of the appendix: an incidental finding in a case of sigmoid diverticular disease.

Benign multicystic mesothelioma is a well recognised but rare entity. The aim of this report is to describe a case of a small mesothelial proliferation of the peritoneum. A 58 year old postmenopausal woman presented with left sided abdominal pain and altered bowel habit. Radiological investigations (barium enema and computed tomography scan of the abdomen and pelvis) were undertaken. An operation was performed for symptomatic sigmoid diverticular disease. Unusually, the appendix was adherent to the sigmoid colon. Microscopy revealed a benign mesothelioma. The patient remains symptom free to date.