Clinical and pathological insights into primary retroperitoneal mucinous tumors: A case report and literature review.

Primary retroperitoneal mucinous tumors are rare. In this study, a 19-year-old female with a giant retroperitoneal ovarian mucinous cystadenoma and superinfection was reported, alongside an analysis of 85 cases. The patient had fever and a palpable mass, with imaging showing a 23 cm x 13 cm x 27 cm cystic lesion and elevated levels of CA199 and ferritin. The tumor was fully removed and confirmed as a mucinous cystadenoma with infection. Our review shows that these tumors mainly occur in young to middle-aged adults (86.1%) and vary in size (3-30 cm) and about 17.3% of tumors are giant (>20 cm). High CA125 and CA199 levels may indicate borderline or malignant changes. The pathology is diverse, often with benign, borderline, and malignant areas in the same tumor and benign types can progress to malignancy. Effective treatment relies on complete surgical removal. Although benign and borderline types have good outcomes, malignant mucinous cystadenocarcinomas have a high recurrence rate (33.3%) after tumor removal alone. This risk is greatly reduced with additional hysterectomy and bilateral salpingo-oophorectomy. Our research highlights the importance of early surgery, and provides practical management advice for this rare condition.