Prenatal ultrasonographic diagnosis of fetal intracranial tumors: a review.

Our objective was to review current literature pertaining to prenatal ultrasonography of various fetal intracranial neoplastic and non-neoplastic tumors. To this goal, all manuscripts published in the English language regarding this topic obtained from a MEDLINE search from 1966 through January 1998 were selected and reviewed. Additional sources were identified through cross-referencing. Intracranial fetal tumors are extremely rare and precise diagnosis is dependent on histology examination of tissue obtained at subsequent surgery or autopsy. Currently, prenatal ultrasonographic findings associated with the following fetal intracranial tumors have been described: teratomas; neuroepithelial tumors including: glioblastoma, astrocytoma, gangliocytoma, medulloblastoma, choroid plexus, and papilloma; and mesenchymal tumors. Non-neoplastic fetal intracranial tumors are even less frequent and include: unilateral megalencephaly, heterotopia, and lipoma of the corpus callosum. Cardinal ultrasonographic findings associated with fetal intracranial tumors include: echogenic and semicystic space occupying lesions with or without distortion of normal symmetrical intracranial (usually midline) structures, calcifications, craniomegaly, polyhydramnios, obstructive hydrocephaly, high-output cardiac failure (hydrops fetalis), the presence of other associated structural anomalies, and infrequently abnormal cerebral Doppler flow velocimetry.