Hydranencephaly in a Newborn: A Case Report and a Review of the Literature.

Hydranencephaly (HE) is a severe and isolated malformation affecting the cerebral mantle. In this condition, the cerebral hemispheres are entirely or almost entirely absent, replaced by a membranous sac filled with cerebrospinal fluid, while the midbrain is usually preserved. Although HE is a relatively rare brain disorder, the differential diagnosis must include conditions such as severe hydrocephalus, porencephalic cysts, and alobar holoprosencephaly. This condition also raises ethical concerns, particularly regarding the criteria for surgical treatment. This case report, accompanied by a review of the literature, discusses the etiopathogenic and diagnostic aspects of HE, as well as its management, illustrated by the antenatal diagnosis of a newborn with HE, confirmed by brain MRI at four days of age.