AKA macrencephaly, AKA megalencephaly. Not to be confused with macrocephaly, which is an enlargement of the skull. Not a single pathologic entity. An enlarged brain may be due to hypertrophy of gray matter alone, gray and white matter, presence of additional structures (glial overgrowth, diffuse gliomas, heterotopias, metabolic storage diseases…).
Conditions in which macrocephaly may be seen include:
● neurocutaneous syndromes (especially neurofibromatosis)
● megalencephaly-capillary malformation syndrome (MCAP): an overgrowth syndrome with megalencephaly (often with hydrocephalus, Chiari malformation, polymicrogyria, and seizures) and capillary malformations in the skin (usually on the face).