Abstract

Exencephalus is a variant of anencephaly. It probably sits morphologically between classic anencephaly and encephaloele. A significant portion of prosencephalon can be recognized in the head where vertex structure is regularly missing. Diencephalon and rhombencephalon are fairly well preserved in almost every case. Microscopically isocortical lamination is present and cerebral vessels are relatively well developed. Recently authors experienced two autopsy cases of these rare anomalies. The first case was a product after 29 weeks gestation from a 26 years old female who had a history of carbon monoxide poisioning during the ear]y gestation period. The baby died 2 hours after delivery. She weighed 1.02㎏. and measured 47.5㎝. in height. She had typical massive exencephalic acrania along with facial and phalangeal anomalies. The exencephalic mass was 9.0×5.0×4.0㎝. and weighed 120gm. Structures suggestive of gyri and sulci were noted, and these structures were confirmed by microscopic examination. The second case was a product after 30 weeks gestation from a 25 years old female who had no noticeable abnormalities during early gestation period. The baby died soon after delivery. He weighed 1.2㎏. and measured 53㎝. in height. He also had typical massive exencephalic acrania. The exencephalic mass was 8.0×6.0×4.0㎝. and was 150gm. in weight. Structures of gyri and sulci were noted, along with opendyma-lined thalamic structure.