Magnetic resonance imaging (MRI), as an adjunct to ultrasonography, has become a promising tool in prenatal diagnosis and therapy. In this report, the authors described a case of giant solid mass arising in the fetal neck region diagnosed by prenatal sonographic examination at the gestational age of 33 weeks’. MRI was used to confirm the diagnosis, and to assist fetal airway assessment. Due to the concern of fetal airway compromise, the ex utero intrapartum treatment (EXIT) was strategically planned with help from specialists in the according fields. This allowed the authors to secure the fetal airway before fetomaternal circulation was disconnected. It was performed successfully through Cesarean section at the time of birth. Histopathology revealed infantile myofibroma, which is a rare form of such a tumor arising on the fetal head and neck region diagnosed prenatally.

Keywords: Fetal MRI, Infantile myofribroma, EXIT, Fetal therapy