Fetal intracranial tumors: a review of 27 cases.

Fetal intracranial tumors are rare. The diagnosis is generally made on histology after birth. The aim of this study was to analyze clinical and imaging data in a series of fetal intracranial tumors and emphasize the findings that may help approach the diagnosis antenatally. We retrospectively analyzed imaging and clinical findings in 27 cases of fetal intracranial tumors assessed by ultrasound (27/27) and MR imaging (24/27). A histological diagnosis was always obtained. Main diagnoses included 15 germinal tumors (13 teratomas), 4 glial tumors, 2 craniopharyngiomas and 3 hamartomas. Average gestational age at diagnosis was 27 weeks for teratomas, 21 weeks for hamartomas and 34 weeks for glial tumors. All tumors but one were supra tentorial, and the lesion extended in the posterior fossa in two teratomas. A heterogeneous pattern, which was more frequently seen in teratomas, was better visualized by MR than US imaging. In addition, in two cases of teratomas, MR imaging better assessed the extension of the tumor. Teratomas and gliomas are the most frequent brain tumors in the fetus. US and MR imagings appear complementary in the prenatal assessment of these lesions.