Anterior mediastinal endodermal sinus (yolk sac) tumor in a female infant.

The first known case of primary anterior mediastinal endodermal sinus (yolk sac) tumor in a female patient, occurring in a 20-month-old infant, is reported. The child presented with cough, fever, and listlessness. Chest x-ray revealed a right anterior mediastinal mass. At thoracotomy a large anterior mediastinal tumor extending from the neck to the diaphragm was found, and was almost totally resected. Microscopically, the tumor displayed many of the histologic patterns observed in EST. Other neoplastic germ cell elements were not identified. The ultrastructural and immunohistochemical findings further confirmed the diagnosis. Serum alpha-fetoprotein (AFP) level, determined during surgery, was elevated to 65,200 ng/ml, whereas serum beta-human chorionic gonadotropin level was normal. Postoperatively, combination chemotherapy consisting of vinblastine, bleomycin, cisplatin, dactinomycin, cyclophosphamide, and doxorubicin was administered with a maintenance program. After 18 weeks on this regimen all the findings were normal, including serum AFP level. The child is well and disease-free 25 months after diagnosis.