increased head circumference
macrocephaly
An abnormally large head and/or brain; in children, macrocephaly is defined as an occipitofrontal circumference of > 3 SD ≥ the mean.DiffDx—non-hydrocephalic causes of macrocephaly
Benign familial form (siblings also have large heads), achondroplasia, Banayan syndrome, cerebral gigantism (with macrosomia or Sotos syndrome), cutis marmorata telangiectatica congenita, fragile X syndrome, Klippel-Trenauny-Weber syndrome, mucopolysaccharidosis, neurofibromatosis, Weaver syndrome.