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.

Brain MRI in fetuses with cardiac tumours.

Tuberous sclerosis complex (TSC) is an autosomal dominant multisystem disorder which affects the skin, brain, heart and other organs. It is caused by mutations of two genes: TSC1 (on chromosome 9q34) or TSC2 (on 16p13.3). 70% of cases are sporadic with new mutations. This study aimed to highlight the utility of prenatal MRI as an adjunct imaging modality in the diagnosis and prognosis of tuberous sclerosis complex. Prenatal ultrasound and magnetic resonance imaging were performed in seven fetuses at a gestational age of 30, 32, 34 and 35 weeks using a 1.5 T MRI scanner. SSFSE,T2- and FGRE/T1-weighted images were obtained in axial, coronal and sagittal planes. Postnatal MRI was performed in two cases. Intracardiac tumors (rhabdomyomas) were revealed on ultrasound in all fetuses. On sonographic examination the brain tissue appeared normal in all cases. Brain MRI revealed focal low-signal-intensity lesions, localized along the walls of the lateral ventricles of five fetuses. Another hypointense lesion was seen at the grey/white matter junction in one case. Brain MRI of two fetuses was normal. The diagnosis of TSC was established in five cases. Postnatal MRI in two cases confirmed prenatal findings. MRI allows more complete evaluation of the fetus and helps to determine the diagnosis and prognosis in cases of TSC. The use of prenatal MR imaging in addition to prenatal sonography has the potential to improve genetic counseling and prenatal diagnosis of patients with tuberous sclerosis.