Abstract

Primary mucinous cystic neoplasms of the retroperitoneum in women are rare and show histologic features similar to their ovarian or pancreatic counterparts. We present three cases of primary retroperitoneal mucinous neoplasms of variable malignant potentials including a cystadenocarcinoma in a 50-year-old woman, a cystic neoplasm of borderline malignancy in a 31-year-old woman, and a cystadenoma in a 67-year-old woman. All cases showed histologic features similar to mucinous tumors of the ovary. Immunohistochemical study demonstrated positivity for calretinin in case 3. The histogenesis of these neoplasms can be assumed most likely to be mucinous metaplasia of the mesothelium or undetected heterotopic pancreatic tissue. Appropriate management is thought to be the same as for analogous ovarian neoplasms.