Natural history of glioma

The natural life history of gliomas is discussed from the viewpoint of early diagnosis of so-called "silent" gliomas and postoperative follow-up study of "inactive gliomas, both types easily detectable by CT scan. On the basis of their functional status, about 10% of 150 histologically proven intracranial gliomas were judged to be silent or inactive gliomas. They were inactive for an average of 8.5 years, and most were fibrillary or gemistocytic astrocytomas except for one grade 3 astrocytoma. cystic formation was seen in two thirds of the cases and calcification in one half. Also, among highly malignant gliomas, a significant difference in the period of survival was seen between the group with very long intervals of 2-3 years, from onset to operation and that with relatively short periods of 2-3 months. Accordingly, treatment policy regarding such silent or inactive gliomas should be carefully determined case by case. Monitoring during postoperative progression-freed intervals is especially useful.