RESUMEN
A male infant was born to a 24-year-old mother (gravida 1 para 1) by cesarean delivery at 33 1/7 weeks of gestation. The physical examination revealed a large mass protruding from the baby's mouth, which appeared to be attached to the palate. Tracheostomy was performed immediately in the delivery room. A partial surgical excision was performed on the second postnatal day, removing most of the teratoma (epignathus), which was attached to the back of the pharynx and protruding from the baby's mouth measuring 13×11×9 cm and weighing 545 g. The final pathological diagnosis was "malignant epignathus with nephroblastoma component." According to our knowledge, this is the first case that have malignant epignathus including nephroblastoma component in the literature.