Navigation-guided endoscopic biopsy for pathological diagnosis for intraparenchymal pure germinoma near the ventricular trigone

BACKGROUND: The authors report a case of intraparenchymal germinoma pathologically diagnosed using navigation-guided endoscopic biopsy. CASE DESCRIPTION: A 27-year-old man had mild left hemiparesis, transcortical motor aphasia, and amnesia. Magnetic resonance (MR) imaging revealed an intraparenchymal mass lesion near the left ventricular trigone. Navigation-guided endoscopic biopsy was performed, and histopathology revealed large neoplastic cells immunohistochemically positive for germinoma-specific antigens, which were diagnosed as pure germinoma. Chemotherapy with whole-brain radiotherapy was performed, and the neurological symptoms did not change during the treatment. Follow-up MR imaging 1 year after the surgery showed no evidence of recurrence or dissemination. CONCLUSIONS: Navigation-guided endoscopic biopsy can be a useful technique in such intraparenchymal germinoma cases.