Mesonephric-like adenocarcinoma of the ovary: A case report and a review of the literature.

Rationale: Mesonephric-like adenocarcinoma (MLA) from ovary is a very rare tumor which derives from mesonephric duct remnant of the female genital tract. Only six cases have been reported so far in the English literature.

Patient Concerns: A 29-year-old female patient was referred to the local hospital with a 20-day history of abdominal discomfort.

Diagnoses: Pelvic ultrasound examination revealed a solid and cystic mass measuring 10 cm in diameter in the right adnexal area and a cystic mass measuring 5 cm in the left adnexal area. Postoperative pathology in the local hospital revealed suspected malignancy of the right ovary, and she was then transferred to our institution for definite diagnosis. The tumor mass was finally diagnosed as a primary MLA arising from the right ovary by histological and immunohistochemical examination in our institution.

Interventions: The patient underwent laparoscopic right adnexectomy and removal of left ovarian cyst in the local institution. Then, she underwent a complete staging surgery including a total hysterectomy, left adnexectomy, pelvic plus para-aortic lymphadenectomy, and omentectomy in our hospital. In addition, she received four cycles of combination chemotherapy with carboplatin plus paclitaxel.

Outcomes: There is no evidence of recurrence with 13 months of follow-up till now, and we are still following-up this patient.

Lessons: MLA is an extremely uncommon malignancy with difficult diagnosis, unclear treatment and poor prognosis. Familiarizing with the clinical features and optimal management of this rare tumor may increase awareness of the disease among clinicians and pathologists, thus avoiding the misdiagnosis and mistreatment.