Sonographic characteristics of linear nevus sebaceous sequence.

Linear nevus sebaceous is a hamartomatous lesion most commonly seen on the face and head of infants and diagnosed after birth. We describe a patient with sonographic findings of linear nevus sebaceous seen initially at 30 weeks' gestation. Other associated sonographic findings include macrocephaly and polyhydramnios. When associated with a midline soft tissue mass, these findings are highly suggestive of the presence of congenital linear nevus sebaceous sequence.