Borderline Serous Papillary Tumor Arising in a Paraovarian Cyst: A Case Report and an Extensive Review of the Literature

Background: Paraovarian cysts are benign cysts that develop near the ovaries and fallopian tubes in the pelvic region. They can cause mass effects requiring excision. In rare cases, tumors may develop inside these cysts. These tumors may be benign, malignant, or borderline. Case Report: A 26-year-old lady presented for excision of a paraovarian cyst. Pre-operative imaging showed the presence of few undulating folds at the periphery of the cyst. The patient underwent laparoscopic pelvic cystectomy without intra-operative drainage. Pathological examination of the specimen revealed a borderline serous papillary tumor protruding from the cyst wall. Conclusion: The occurrence of a borderline tumor, also known as a tumor of low malignant potential, in a pre-existing paraovarian cyst is very rare and has only been reported few times in the literature. A thorough review of these cases showed that the most common imaging finding that raises suspicion for a borderline tumor within a paraovarian cyst is the presence of small intracystic projections within the unilocular adnexal cyst. However, since evaluating the presence of an intracystic tumor is not always possible, performing a fertility-preserving laparoscopic cystectomy without cyst content spillage, is recommended. If properly excised, the prognosis of this tumor is good, and recurrence is rare.