Congenital infiltrating lipomatosis of the face with ipsilateral hemimegalencephaly, band heterotopia, and hypertrophy of brainstem and cerebellum.

The simultaneous appearance of congenital infiltrating lipomatosis of the face that causes facial hemihypertrophy and ipsilateral hemimegalencephaly is extremely rare. We report a 4-year-old boy with congenital facial asymmetry and infantile-onset epilepsy. Magnetic resonance imaging (MRI) results led to the diagnosis of infiltrating lipomatosis of the face; the diagnosis was confirmed on the basis of the results of pathological examinations. Additionally, brain MRI revealed ipsilateral hemimegalencephaly, associated with band heterotopia and the hemihypertrophy of the ipsilateral brainstem and cerebellum. He had no nevi or other skin abnormalities suggesting neurocutaneous syndrome. His seizures were so intractable that they necessitated functional hemispherectomy. The lipomatous lesion was successfully resected without relapse. Psychomotor delay and left hemiplegia were observed at the last follow-up.