Intracranial Malignant Teratoma Diagnosed in a Fetus

The authors describe a case of intracranial malignant teratoma in a 28-week fetus, discovered on assessment of the mother's excessive abdominal enlargement. Alpha-fetoprotein levels in amniotic fluid and serum were high. Ultrasonography revealed a large, solid intracranial mass. The fetus was viable until completion of a cesarean delivery, at which time the heart stopped. At autopsy, the fetal brain was found to have been extensively replaced by a solid, cystic tumor, which proved to be a malignant teratoma comprising elements of all three germ cell layers. The authors' experience and review of the reported cases indicate that prenatal malignant intracranial teratoma can be safely and accurately diagnosed, and that immediate delivery or cranial decompression may be advisable when the diagnosis is established. The usefulness and limitations of ultrasonography are particularly emphasized.