Prenatal diagnosis of severe epignathus in a twin: case report and review of the literature.

A prenatal ultrasound diagnosis of epignathus in a dichorionic-diamniotic twin pregnancy is reported. A complex mass protruding from the fetal face was seen at week 19. Amniocentesis resulted in a 46,XX fetus with elevated alpha-fetoprotein (α-FP). An increase in tumor size and severe polyhydramnios ensued. Selective feticide performed at 22 weeks led to untreatable uterine contractions with iatrogenic abortion and early neonatal mortality of the healthy cotwin. Without development of polyhydramnios and tumor growth, weekly scan and transvaginal cervical assessment would have been carried out and cesarean section planned at around 32 weeks. Necroscopy and histology aided the ultrasound-based prenatal diagnosis.