Acrania: an autopsy case and review of the literature

ABSTRACT We report an autopsy case of acrania with a review of the literature. A 31-year-old woman was admitted in poor genaral condition and diagnosed as pregnant at the 26th week of gestation. The fetus was suspected to be anencephalic or hydrocephalic by ultrasonography. She delivered a stillbirth male baby at the 28th week of gestation. Autopsy showed the cranium lacked the cranial vault The scalp directly covered the hydrocephalic brain without calvaria. No cerebellum was found macroscopically. On histological examination, the thinned cerebral layer was composed of white matter-like brain tissue with glial and ependymal cells. In the cerebral layer near the base of the skull, a few NSE-positive neurons among many GFAP-positive glial cells and oligodendrocyte-like cells were observed. The choroid plexuses were observed inside the ependymal layers. The brain stem and the spinal cord were normally preserved with clusters of NSE-positive neurons. Agnethia and horseshoe kidney were combined as malformations other than the brain. We reviewed 42 cases of acrania from the literature.