Facial infiltrating lipomatosis with hemimegalencephaly and lymphatic malformations caused by nonhotspot phosphatidylinositol 3-kinase catalytic subunit alpha mutation.

We report an unusual case of facial infiltrating lipomatosis with hemimegalencephaly and lymphatic malformations. In addition to the clinical data and imaging findings, detection of a heterozygous PIK3CA nonhotspot known pathogenic variant C420R in a facial epidermal nevus provided novel insight into the pathogenic effect of somatic PIK3CA mutations.