[Ultrastructure of cerebellar hemangioblastoma].

Authors describe the fine structure of the border zone of a cerebellar hemangioblastoma. This electron microscopie study corroborates all the previous optic microscopic results concerning absence of a well delimited bound between hemangioblastoma and bordering cerebellar tissue. Different stages of peculiar cellular degeneration are found, and an attempt for interpretation is given. However these morphologic changes are insufficient to allow further explanation about the histogenesis of hemangioblastomas, which remains unknown.