Concurrent high-grade serous carcinoma and borderline tumor demonstrating different chemo-sensitivity

Ovarian high-grade serous adenocarcinoma responds well to regular platinum/taxane chemotherapy, while borderline tumor survives and demonstrates persistent disease. A 69-year-old Japanese woman was suspected for having advanced ovarian carcinoma. MRI showed cystic tumor containing solid component of the right adnexal region with massive ascites and peritoneal dissemination. Serum CA125 was elevated to 203 µ/ml; however, no remote metastases were detected. Laparotomy revealed that peritoneal carcinomatosis spreads out to omentum and subphrenic area. Omentum was partially removed with big tumor nodules that histologically demonstrated the high-grade serous adenocarcinoma with positive ascites cytology. After 6 cycles of postoperative chemotherapy with docetaxel and carboplatin, she received second surgery where the known residual bilateral adnexa and all of the persistent tumors were perfectly resected. Pathological examination of the tumor revealed serous borderline tumor with microinvasion and no evidence of residual high-grade serous carcinoma with negative ascites cytology. This is the extremely rare case of concurrent high-grade serous carcinoma and borderline tumor demonstrating differential chemo-sensitivity.