[Retrocerebellar cysts and cysts of the tentorial hiatus in children (author's transl)].

A series of 11 children is reported with retrocerebellar cysts or cysts of the tentorial hiatus. The principal symptom is hydrocephalus of early onset (before 3 months of age in 6/11 cases). Neuroradiological examination usually shows only an expansive lesion of the posterior fossa, and occasionally the cyst itself. These classically called arachnoid cysts are probably glio-ependymal in origin.