Retroperitoneal mucinous cystadenoma.

Twelve cases of retroperitoneal mucinous cystadenoma or mucinous cystadenocarcinoma in women have been reported in the literature. We report an additional case. The histogenesis of mucinous cystadenomas and mucinous cystadenocarcinomas in the retroperitoneum is not clear, but that these lesions may arise from teratomas, ectopic supernumerary or accessory ovaries, or coelomic metaplasia has been suggested. It is possible that small clusters of coelomic epithelial cells could be deposited along the route of ovarian embryonic descent and, by proliferation or metaplastic differentiation, develop into these cystic tumors. The histogenesis of the rare histologically similar lesions that have been seen in men is even less clear.