Hypothalamic polar spongioblastoma associated with the diencephalic syndrome

A tumor was resected from the third ventricle of a four years and eleven month old girl with the diencephalic syndrome. By light microscopy, it was diagnosed as a polar spongioblastoma.Its ultrastructural study was undertaken and the features were found to be distinctive and previously unreported. The organization of the neoplasm was similar to that of the hypothalamic neuro-endocrine systems: Cellular perivascular arrangement with intra-cytoplasmic microtubules and membrane bound dense-core granules.