Macrocephaly

This code represents an abnormally large head circumference for an individual's age and sex, exceeding two standard deviations above the mean. It can be a benign familial trait or indicate an underlying medical condition such as hydrocephalus, brain tumors, or genetic syndromes.

Assign this code when documentation explicitly states macrocephaly, often identified during routine pediatric examinations or when a patient presents with neurological symptoms. Supporting documentation includes head circumference measurements plotted on growth charts, physical exam findings, and imaging reports confirming increased head size.

• Differentiate from hydrocephalus (G91.-) unless hydrocephalus is explicitly documented as the underlying cause.
• Always code any underlying cause of macrocephaly first, if known and documented.
• Ensure documentation specifies "macrocephaly" and not just "large head" without further clinical context.