[Intracerebellar schwannoma].

Only some rare examples of schwannomas localized in the medullary parenchyma are cited in the literature. The first was described by Kernohan in 1933; 9 cases were rapported in the thirty following years. For Brain a few observations about one case were cited by David (1965), Gibson (1966), New (1972) and Ghatak (1975). The authors relate one case of isolated schwannoma in superior vermis. That was a 15 years old young man who had a low evoluting I.C.P. syndrome. The pre-operating neurological investigation revealed a small cerebellar syndrome. The neuroradiological record allowed to localize an expansive median affection in the posterior fossa on a level with the Sylvius aqueduct. The neurosurgical operation allowed to carry off a tumor from the superior vermis; schwannoma tissue was the conclusion of the histological study. The evolution has been good and no cranial nerves were involved. Different theoris about the localisation of Schwann cells in this region are described.