A case of an epignathus with intracranial extension appearing as a persistently open mouth at 16 weeks and subsequently diagnosed at 20 weeks of gestation.

We report a rare case of oral mass (epignathus) with intracranial extension originally suspected antenatally at 16 weeks' gestation because of a persistent open mouth. Postmortem MRI and pathologic examination of the fetus confirmed an oral teratoma with bilateral ventricular dilatation, corpus callosum agenesis, and a neuroepithelial intracranial cyst. The relevant literature regarding this anomaly is reviewed.