Retroperitoneal mucinous cystadenoma - Report of a case with reference to histogenesis

Primary retroperitoneal mucinous cystadenoma is an uncommon tumor found exc lusively in women. Herein, we describe a patient who had resection of a lar ge retroperitoneal cystic mass. Histologic, immunohistochemical, and electr on microscopic examination of the lining epithelial cells showed features o f mesothelial cells in addition to ovarian mucinous cystadenoma. These find ings suggest that these tumors arise from inclusions of mesothelial cells a nd subsequent mucinous metaplasia of the lining cells to form a cystadenoma . Estrogen receptors may be implicated in tumor promotion, explaining the o ccurrence exclusively in women.