MRI in the Diagnosis of Fetal Intracranial Teratoma

Abstract

Fetal intracranial tumors are rare but, when they do occur they are associated with high fetal mortality. Many of the congenital brain tumors often result in intrauterine fetal death, limiting accurate assessment of tumor prevalence and incidence. The most frequent is teratoma, which is characterized by cells dependent on the three germ layers. These tumors are usually detected in the usual prenatal control ultrasounds, and are often so large that it is difficult to determine their origin. When ultrasound suspicion exists, a fetal MRI study is recommended. The case of a 20- week pregnant woman is presented, in which a fetal intracranial tumor was detected on a prenatal control ultrasound. It was decided to complete the study with a fetal MRI in which a pineal gland mass with anterior extension, compatible with teratoma, was visualized. Voluntary termination of pregnancy was decided, and the histological study after necropsy confirmed that it was an immature teratoma. MRI is the imaging test of choice after suspected diagnostic ultrasound, as its high resolution provides relevant information that allows better assessment of the internal architecture of the tumor, as well as its origin and extension. In addition, it also serves to evaluate the rest of the intracranial structures.