Congenital CNS tumors diagnosed on prenatal MRI

Congenital tumors form a unique group among pediatric neoplasms. They are different from other tumor groups in this population not only due to the onset time but also to their histopathology, anatomic location, biologic behavior and prognosis. The development of fetal MRI allowed early diagnosis of these tumors. Three fetuses with congenital central nervous system (CNS) tumors were diagnosed prenatally and confirmed with histopathology. Prenatal ultrasonography (US) and magnetic resonance imaging (MRI) were performed. After birth MRI or computed tomography (CT) were carried out. In one case a large intra-axial brain tumor was diagnosed with solid, cystic and hemorrhagic elements. After surgery the tumor turned out to be choroid plexus carcinoma. In the second case craniopharyngioma arising from the suprasellar region was diagnosed on the basis of prenatal MRI and confirmed. In the third case extra-axial meningioma-like tumor was visualized on fetal MRI. After surgery it turned out to be desmoplastic infantile astrocytoma. Intracranial teratoma, the most typical CNS congenital tumor, was not diagnosed in our material. Our cases were rarely encountered neoplasms: choroid plexus carcinoma, craniopharyngioma and desmoplastic infantile astrocytoma. The examinations were repeated after birth and did not add significant information. In utero diagnostics is easier and safer than postnatal imaging of the sick baby that may require life-support equipment, and provides information of equal value.