Epidemiology of germ cell tumors in Asia of pineal region tumor.

A higher incidence of pineal region tumors in Asian countries compared to Western countries has been reported. In the Brain Tumor Registry of Japan (BTRJ), there were 38,273 primary brain tumors except those of unknown histology (1123 cases) registered in the period between 1984 and 1993, in which 807 pineal region tumors with 104 unknown histology were registered in BTRJ. Of these pineal region tumors, germ cell tumors had the highest frequency, 70.3%, followed by pineal parenchymal tumors, 12.0%; pineocytoma in 7.8% and pineoblastoma in 4.2%. Limited to germ cell tumors, germinoma was 68.0%, then teratoma including malignant teratoma, had the second high frequency, 14.7% in pineal region. While data reported by Allaire et al. and Edwards et al. revealed that the incidence of germinoma was 88.6%, 52.4% of germ cell tumors in pineal region in France and in USA, respectively. Although number of cases is very small, it is suggested that the percentage of germinoma in germ cell tumors in the pineal region might be almost the same in Western countries as in Asian countries, and the occurrence of germ cell tumors in the pineal region was much higher than those in Asia. Age and gender distribution of pineal region tumors indicated that germ cell tumors and pineocytoma showed a high incidence in males and in children. Most of malignant pineal region tumors other than germinomas showed poor prognosis, but recent progress in surgical techniques and effective chemotherapy will improve the prognosis.