Epidermal nevus syndrome with hemimegalencephaly: a clinical report of a case with acanthosis nigricans-like nevi on the face and neck, hemimegalencephaly, and hemihypertrophy of the body.

A 5-year-old boy with the epidermal nevus syndrome and hemimegalencephaly is reported. He had pigmented nevi on the forehead and neck, and hemihypertrophy of the body from the birth. He developed intractable seizures, mental retardation, and right hemiparesis. His seizure pattern changed from early infantile epileptic encephalopathy to infantile spasms at 2 months of age. Electroencephalograms showed a suppression-burst pattern in the neonatal period, subsequently changing to hypsarrhythmia. Computerized tomography of the brain disclosed slight dilatation of the posterior horn of the lateral ventricle at the age of 2 months. Later, hemimegalencephaly with calcification on the left side of the brain was noted. Histological examination of the pigmented nevus on the neck showed it to be an acanthosis nigricans-like lesion. Clinical differences between tuberous sclerosis and epidermal nevus syndrome with hemimegalencephaly are discussed.