Primary retro peritoneal mucinous cystadenoma

Mucinous cystadenomas and cystadenocarcinomas of the ovary are clinically and histopathologically well-established common tumors. The retroperitoneal location of cystic tumors resembling ovarian mucinous cystadenoma and cystadenocarcinoma is rare. We report the clinical and pathological features of a rare retroperitoneal tumor in the presence of normal ovaries, primary retroperitoneal cystadenoma, and discuss the possible origin of retroperitoneal mucinous cystadenomas.