Prenatal ultrasound and magnetic resonance imaging findings of a hypovascular epignathus with a favorable prognosis.

Epignathus of a fetus is an extremely rare type of an oropharyngeal teratoma that commonly arises from the palate and often grows in the prenatal period, leading to polyhydramnios due to difficulty in swallowing before birth and a high mortality due to the airway obstruction after birth. We report here a very rare case of a fetus with an epignathus decreasing in size naturally in the prenatal period with a favorable prognosis. In contrast to previously reported cases of epignathus that grew rapidly in the prenatal period, color Doppler fetal ultrasound showed a hypovascular tumor in our case. Moreover, histopathologic examination revealed an epignathus with necrotic areas inside. Based on our experience, a hypovascular epignathus demonstrated by color Doppler fetal ultrasound may be an indicator of a favorable prognosis.