Magnetic resonance imaging (MRI) which was taken subsequently confirmed the result of ultrasound. Meanwhile, it also provided more detailed information on the fetal central nervous system (CNS) including fetal brain dysplasia and the possible compression of optic nerves caused by the tumor (Fig. 2). The parents were informed that the most likely diagnosis was optical nerve glioma; however, the malignant intracranial tumor was difficult to be excluded prenatally.