RESUMEN
We report a case of primary endodermal sinus tumor of the omentum in a 46-year-old woman. The patient had been referred to our hospital for pain in the right abdomen. CT scan revealed a right-sided abdominal mass. At laparotomy, a large omental tumor extending to the bowel, uterus, ovaries and peritoneum was found, and it was totally resected. The tumor displayed the typical histological patterns observed in endodermal sinus tumor, and the immunohistochemical findings confirmed the diagnosis. Serum AFP level was 21.550 ng/ml prior to laparotomy, and decreased to 13.845 ng/mL after surgery, whereas the level of serum beta human chorionic gonadotropin was normal. Post-surgery, the patient received combination chemotherapy consisting of cisplatin, etoposide and bleomycin every 3 weeks for a total of 6 cycles. At the end of the treatment, all the findings, including AFP level, were normal.