Germinoma with malignant transformation to nongerminomatous germ cell tumor.

The authors describe the case of a young girl with suprasellar germinoma. Six weeks after this diagnosis, just prior to initiation of therapy, serum and CSF marker analysis revealed sudden and marked elevation of alpha-fetoprotein, indicating transformation of her germinoma to a nongerminomatous germ cell tumor. She underwent chemotherapy and radiation therapy per the national treatment approach for the new diagnosis, with subsequent return of her serum and CSF tumor markers to normal levels. To the authors' knowledge, this is the first case in the English-language literature of a nongerminomatous germ cell tumor resulting from conversion of germinoma at the original site of presentation.