Fetal magnetic resonance imaging of a hypothalamic hamartoma in Pallister-Hall Syndrome

Introduction: Pallister-Hall syndrome is a pleiotropic disorder of human development. It is characterized by postaxial polydactyly, hypothalamic hamartoma, imperforate anus, bifid epiglottis, renal abnormalities and pulmonary segmentation anomalies. We describe a unique case where MRI of the fetal brain allowed the prenatal diagnosis of PHS.

Case report: In the 37th week of gestation, fetal sonography revealed hexadactyly of the right foot and an unclear intracranial lesion with suspicious dilatation of the third ventricle was described. Fetal MR images demonstrated a large suprasellar and prepontine mass. The infundibulum was displaced anteriorly, and the optic chiasm was elevated. Posterior displacement of the pons and midbrain with superior elevation of the third ventricle was visible. MRI showed heterogeneous appearance of the tumor with mixed signal intensities equivalent to white and gray matter of remaining normal brain and a central cystic component. The diagnosis of PHS was made. After birth by Cesarean section, conservative management was elected with follow-up by transcranial ultrasound. At the age of ten weeks, when the girl presented with epileptic seizures, the tumor had grown proportionally with head size. MRI showed the hypothalamic hamartoma to displace the optic chiasm, the pons, cerebellar hemispheres, and temporal lobes. Its signal characteristics were equivalent to fetal MRI.

Conclusion: Fetal MRI is used with increasing frequency as an adjunct to ultrasound in prenatal diagnosis. It has advantages in demonstrating pathology of the brain, lungs, complex syndromes, and conditions associated with reduction of amniotic fluid.