An unusual primary omental tumor: Mixed germ cell tumor

Abstract

Abstract Primary tumors of the greater omentum are rare. Mixed germ-cell tumor, which is derived from germ cells, occurs mainly in gonad of adolescents and young adults. In the present case, we report a 58-year-old woman, who was admitted to the hospital because of abdominal discomfort. Magnetic resonance imaging revealed a large mass in the left lower quadrant. Pertinent laboratory tests were within normal limits except for a rise in serum alfa-fetoprotein. During laparotomy, a solitary mass arising from the greater omentum was confirmed. She underwent omentectomy. Histological examination showed the tumor composed of yolk sac tumor, embryonal carcinoma and dysgerminoma that were immunopositive for alfa-fetoprotein, CD30 and CD117, respectively. Finally, the diagnosis was primary omental mixed germ-cell tumor. She received four cycles of systemic chemotherapy and was followed-up for 18 months without recurrence or metastasis. Although primary omental tumor is uncommon, the possibility of mixed germ-cell tumor should be considered by both physician and surgeon.