Cystic mucinous tumours of the mesentery and retroperitoneum: report of three cases.

A mucinous cystadenoma of the mesentery and two borderline mucinous cystadenocarcinomas of the mesentery and retroperitoneum are reported. The patients were females, aged 38, 47 and 58 years. The cysts showed identical features to those commonly seen in the appendix and ovary. One of our cases, with 'borderline' histology, developed metastases to mediastinal lymph nodes, 4 years after diagnosis. We suggest that these tumours develop through mucinous metaplasia in pre-existing mesothelium-lined cysts, the latter being the commonest cysts in this location.