Аннотация:The co‐existence of an endometrioid adenocarcinoma with an ovarian yolk sac tumor is very rare. Only eight cases have been reported in the English language literature. A 54‐year‐old postmenopausal woman with a 6‐month history of progressive abdominal distension was seen at our hospital. MR imaging revealed a large cyst with a solid intramural node. Serum α‐fetoprotein and CA125 levels were 13143 ng/ml and 170 U/ml, respectively. At laparotomy, a large tumor approximately 20 cm in diameter was found to occupy the abdominal cavity, adhering to the swollen appendix and part of the omentum. Microscopically, foci of endometrioid adenocarcinoma together with a yolk sac tumor component were observed within a large endometriotic cyst. Since the tumor was clinically staged 1c, the patient was given 500 mg of intraperitoneal carboplatin postoperatively, followed by five courses of combination chemotherapy consisting of cisplatin, etoposide and peplomycin at 4‐week intervals. The levels of both serum α‐fetoprotein and CA 125 decreased gradually to normal ranges and remained normal at the most recent follow‐up on 29 December, 2001. In contrast to a very poor prognosis of this tumor in previously reported cases, our patient showed no sign of recurrence during a 21‐month follow‐up period.
