Coexistence of Intracranial Germ Cell Tumor with Growing Arteriovenous Fistula.

Abstract

A 26-year-old man was admitted with complaints of progressive depressive mood and general fatigue. Magnetic resonance imaging revealed diffuse enhanced lesions in the neurohypophyseal, pineal, and paraventricular regions and ventricular wall. Endoscopic biopsy confirmed the presence of germ cell tumor, and chemoradiation therapy (CRT) was then performed. Most of the tumors disappeared after CRT except for the right paraventricular lesion. Follow-up magnetic resonance imaging performed 14 months after CRT showed enlargement of this residual lesion. In addition to tumor growth, coexistent flow void signals within the tumor increased. Angiographically, this vascular lesion mimicked arteriovenous malformation, which was mainly fed by the lenticulostriate artery and drained into the internal cerebral vein. Transarterial embolization was performed, resulting in effective flow reduction. Subsequently, the tumor was resected without complications. It was histopathologically diagnosed as a mature teratoma with an arteriovenous fistula (AVF). Arterial components were observed to directly connect to venous components within the tumor without any intermediate nidal components. To the best of our knowledge, this is the first reported case of an intracranial germ cell tumor coexistent with a growing AVF. AVF developed within a CRT-refractory teratomatous component, which was successfully treated with embolization followed by surgical resection.