GERM-20. NEUROENDOSCOPIC BIOPSY OF INTRACRANIAL GERM CELL TUMORS: ACCURACY AND COMPLICATIONS

Abstract

Intracranial germ cell tumors (GCTs) are a heterogeneous group of lesions. It is important to obtain the accurate histological diagnosis since the treatment outcomes can depend on histology. Neuroendoscopic biopsy is a minimally invasive procedure and employed widely. But it is not yet clear whether neuroendoscopy can make so accurate diagnosis as craniotomy without increasing the risk of dissemination. We compared the diagnostic rate and recurrence rate of these two procedures. Forty patients with intracranial GCTs treated in our institute from 2007 to 2017 were included in this study. More than 6 pieces of tumor tissues were obtained with neuroendoscopy. As highly elevated tumor marker signifies highly malignant tumor, we started treatment without a histological diagnosis. For all patients except those with extremely highly elevated tumor markers, the histological diagnoses were made by neuroendoscopy or craniotomy. Of number cases with germinoma, 3 cases (neuroendoscopy 2, craniotomy 1) relapsed. All three cases were treated with additional chemotherapy and/or radiotherapy to survive. Of number cases with intermediate risk group tumors, 1 case who underwent craniotomy developed recurrence. High-risk tumors were diagnosed by tumor markers in 2 patients, 5 by endoscopy and one by craniotomy. One patient thought to be intermediate risk group by tumor marker, obtained the histological diagnosis of yolk sac tumor. The recurrence rate for neuroendoscopy and craniotomy was 8% and 15% respectively. Neuroendoscopy is useful for histological diagnosis as well as craniotomy and would not increase recurrence rate.