[Epignathus: prenatal diagnosis by sonography and magnetic resonance imaging]

Prenatal diagnosis of a teratoma of the oral cavity (epignathus) is presented using ultrasonography and magnetic resonance imaging as complementary techniques. Chromosome analysis from amniotic fluid revealed an inverted duplication of chromosome 1 that was confined to the tumour, whereas the constitutional karyotype was normal. The development of polyhydramnios, presumably reflecting impaired fetal swallowing, led to premature rupture of membranes and spontaneous delivery at 23 + 4 weeks of pregnancy. The premature neonate succumbed to acute respiratory distress secondary to airway obstruction by the tumour, and died immediately after birth.