10121-BT-8 CLINICOPATHOLOGICAL ANALYSIS OF CENTRAL NERVOUS SYSTEM GERM CELL TUMORS -387CASES IN THE JCCG COHORT AND THE IGCT CONSORTIUM COHORT

Abstract

Abstract BACKGROUND Central nervous system germ cell tumors (CNS GCTs) are rare primary tumors that tend to occur in East Asian boys. In Japan, the Japan Children's Cancer Group (JCCG) and the CNS GCT Genome Analysis Consortium (iGCT Consortium) have been accumulating clinical and pathological data on CNS-GCT cases. METHODS Statistical analyses were performed on 178 cases in the JCCG's Solid Tumor Observational Study (2016-2022) and 209 cases in the iGCT Consortium (2011-2021) for age, gender, site of origin, and pathological diagnosis. RESULTS There were 306 primary cases and 44 recurrent cases, 296 (77%) males and 90 (23%) females, with a median age of 13 years, 11 years for JCCG and 16 years for iGCT Consortium, with differences between these two cohorts. The most common pathological diagnosis was germinoma in 200 cases (52%). Non-germinomatous germ cell tumors (NGGCTs) in 167 cases (43%), of which 69 cases (18%) were mixed GCT with germinoma, 34 cases were immature teratoma, mature teratoma in 32 cases (8%), yolk sac tumor in 20 cases (5%), mixed GCT without germinoma in 5 cases (1%), choriocarcinoma in 5 cases (1%), embryonal carcinoma in 2 cases (0.5%). The median age of patients with germinoma was 15 years, while with other histological types was 12 years. The pineal gland was the most common site (208 cases, 56%) and 114 cases (31%) occurred in the neurohypophysis. 38 cases of them were bifocal. Tumor development in the basal ganglia occurred in 40 cases (11%), and multiple lesions were seen in 37 cases (10%). In the neurohypophysis, the male-to-female ratio was 1:1, while in the pineal region was 11:1. In the neurohypophysis, 67% had germinoma and 9% had teratoma, whereas, in the pineal regions, 50% had germinoma and 19% had teratoma. CONCLUSIONS CNS GCT is closely correlated with age, sex, site of origin, and histology.