Rapid Growth of an Ovarian Clear Cell Carcinoma Expressing LH/hCG Receptor Arising from Endometriosis during Early Pregnancy

The complete clinical course of a case of ovarian clear cell carcinoma expressing luteinizing hormone (LH)/human chorionic gonadotropin (hCG) receptor arising from endometriosis in a pregnant woman is presented. A 31-year-old woman visited a private clinic in May 1993 for screening tests for infertility. Transvaginal ultrasonography revealed no abnormal findings in the uterus or ovaries. Her menstrual cycle was regular; however, a slight luteal insufficiency was noted. She had been treated with clomiphene, and soon became pregnant. She was diagnosed to be at 5 weeks gestation in June, and at the same time, an ovarian tumor with the diameter of 5 cm was identified. Since the tumor had grown rapidly and was 9 cm in diameter 1 week later, she was referred to our hospital. When she was admitted to our hospital at 9 weeks gestation, the tumor diameter was 14 cm and we found the solid portion within the ovarian tumor. The levels of the tumor markers CA125 and CA19-9 were 106 and 51 U/ml, respectively. The crown-rump length of the fetus (24 mm) was compatible with the gestational age, and fetal heartbeat was confirmed. Under the diagnosis of ovarian carcinoma, right salpingo-oophorectomy was performed at 10 weeks of gestation. Postoperative histological examination revealed a clear cell carcinoma and endometriosis of the right ovary. Immunohistochemically, the clear cell carcinoma stained positively for LH/hCG receptors and estrogen receptors, but not progesterone receptor. No malignant cells were detected by ascitic cytology. Exploratory specimens obtained at the time of operation from the left ovary and pelvic lymph nodes exhibited no malignant cells. Based on these findings, the pregnancy was allowed to proceed, and she delivered a 3010-g male baby at 39 weeks of gestation. She had no signs of recurrence for 2 years after the operation.