Case of the month: Congenital cerebral primitive neuroectodermal tumor (PNET)

A 29-week gestational age newborn male infant was found to have an echogeni c mass in the 3rd ventricle by prenatal ultrasound 2 weeks prior to deliver y. At delivery he was poorly responsive and had hydrocephalus and ascites. A CT scan after birth showed cerebral infarction, amorphous tissue in the l eft hemisphere and numerous calcifications. Despite supportive treatment he died 4 days after birth. Postmortem examination of the brain revealed mark ed distortion of the architecture and a supratentorial undifferentiated neo plasm consistent with a PNET The tumor showed extensive areas of hemorrhage and necrosis and involvement of lateral and third ventricles, brain parenc hyma, and meninges.