Periventricular metastases of a primary intracranial alpha-fetoprotein-producing germ cell tumor.

Periventricular subependymal lesions were found on CT scan in a young man with growth failure, diabetes insipidus, mental deterioration, and hypogonadism with delayed puberty. An initial very good response to radiotherapy was followed a few months later by a relapse, presenting as a very large tumor in the base of the frontal lobes. Serum alpha-fetoprotein at the time of the relapse was very elevated suggesting that the tumor was largely composed of an endodermal sinus tumor component, which was confirmed at autopsy. The purpose of this report is to stress the importance of the use of tumor markers in a particular clinical and neuroradiological setting.