Complete absence of the cerebellum: a report of two cases.

Complete absence of the cerebellum is an extremely rare malformation. Most previous cases have had some remnant of cerebellar cortex, however small. We report two infants with complete absence of the cerebellum. One infant had hydrocephalus and numerous other malformations. The other infant had micrencephaly, which has not previously been reported in association with an absent cerebellum.