Cerebellar hemangioblastoma symptomatic during pregnancy.

An 18-year-old woman presented during the 2nd month of her pregnancy with noncommunicating hydrocephalus due to a cerebellar hemangioblastoma. The tumor rapidly enlarged over a 12-day period after ventriculoperitoneal shunting, probably because of expansion of the vascular compartment. Serial computed tomography and magnetic resonance imaging observations support previous speculations in the literature that vascular engorgement of hemangioblastomas probably accounts for the rapid deterioration of some patients during pregnancy.