Endodermal sinus tumor: a clinical and pathological correlation.

Endodermal sinus tumors occur in the gonads and in a variety of extragonadal locations, particularly as the malignant component of sacral teratomas. Light and electron microscopic studies as well as the presence of alpha fetoprotein support the concept that these lesions arise from germ cells that migrate from the extraembryonic yolk sac. These tumors in all locations are highly malignant and metastasize to lymph nodes, lung, liver and bone. Peritoneal implants are seen from tumors in the ovary, testis, and following ventriculoperitoneal shunts for yolk sac tumors of the pineal gland. There is no satisfactory therapy for the endodermal sinus tumor, regardless of location, when there are distant metastases at the time of diagnosis; however, we have documented complete regression of metastases in one child following therapy with vinblastine, bleomycin, and cis-platinum. Nine of 13 boys with endodermal sinus tumors of the testis survived in this series of patients. All survivors were treated with orchiectomy and lymph node excision. Surgical excision combined with chemotherapy and radiation led to survivors in children with large extragonadal pelvic and retroperitoneal tumors. We recommend vigorous multimodal therapy with surgery and chemotherapy. Radiation is given to the primary lesion when it is too extensive for initial resection or to eradicate residual disease following chemotherapy. Alpha fetoprotein is a valuable tumor marker.