[A child with successfully treated posterior mediastinal endodermal sinus tumor].

A 15-month-old boy with posterior mediastinal endodermal sinus tumor is reported. The patient was admitted with recurrent hemothorax, and his serum alpha-fetoprotein level was 29,520 ng/ml. After removal of the posterior mediastinal tumor, VAC therapy (vincristine, actinomycin D, cyclophosphamide) was started. The chemotherapy was continued 18 months. The patient continues to do well with no sign of tumor and a normal alpha-fetoprotein level 53 months after the operation and 35 months after the completion of therapy. He is the youngest patient documented in the literature and successfully treated for mediastinal endodermal sinus tumor.