macrocephaly
Pronunciation: MAK-ro-SEF-ah-lee
Abnormally large head circumference, typically defined as greater than the 97th percentile for age and sex.
Full Definition
Macrocephaly refers to a head circumference that exceeds the 97th percentile for the child's age and sex, or is more than 2 standard deviations above the mean. This condition can be familial (benign) or associated with underlying pathology such as hydrocephalus, brain tumors, or metabolic disorders. In pediatric practice, serial head circumference measurements are crucial for identifying macrocephaly and determining whether further investigation is warranted. The condition should be distinguished from megalencephaly, which refers specifically to an enlarged brain.
Usage
Usage note: Distinguish from megalencephaly, which refers specifically to brain enlargement.
In Context
- "The infant presented with macrocephaly at the 6-month well-child visit." — Pediatric examination note
- "Family history of macrocephaly suggested a benign familial variant." — Genetics consultation