Huge primary retroperitoneal mucinous cystadenoma of borderline malignancy mimicking an ovarian mass: case report and review.

BACKGROUND Primary retroperitoneal mucinous cystadenoma is a rare tumor only 48 cases have been reported in international literature. Patients affected by primary retroperitoneal mucinous cystadenoma/cystadenocarcinoma ranged in age from 17 to 86 years (median, 42.3 years) and the size of the cystis ranged from 5 to 35 cm (median, 16.1 cm). There is no unanimous opinion on the genesis of these tumors and, due to their extreme rarity, its histogenesis, biological behavior and the optimal management strategy remain at a speculative level. CASE REPORT We report the case of a huge borderline primary retroperitoneal mucinous cystadenoma (24 x 25 cm) in a 35-year-old woman and the strategies adopted for the diagnosis and surgical management. CONCLUSION Primary mucinous cystic tumor of the retroperitoneum was correctly diagnosed only at the time of surgery. As well as in the majority of cases reported in the literature, preoperative investigations were not able to give information about the tumor site. In spite of the short follow-up (two years), the patient's favorable course supports the hypothesis that primary retroperitoneal mucinous cystadenoma may be treated in the same manner as a primary ovarian tumor of the same grade and comparable stage.