THIS MALE INFANT was born at 41 weeks' gestation to a 20-year-old, gravida 3, para 2 woman with an unremarkable medical history, normal prenatal test results, and no smoking, drug use, or other harmful habits. Pregnancy was complicated by decreased fetal movements during the last week of gestation. An ultrasound performed the morning before delivery revealed severe hydrocephalus. A previous ultrasound performed at the 20th week showed no abnormalities. The infant was delivered by emergency cesarean section without complications or need for resuscitation. Apgar scores were 7 and 9 at 1 and 5 minutes, respectively. His birth weight was 4054 g (>95th percentile for age), length was 51 cm (75th percentile), and head circumference was 40 cm (>95th percentile). He was transferred to the neonatal intensive care unit for further evaluation and management.
On physical examination the infant had normal vital signs. He had marked macrocephaly, a full anterior fontanel measuring 5 × 4 cm and a full posterior fontanel measuring 5 × 3 cm. Results of the remainder of the examination were normal. Complete blood cell count, blood chemistry analysis, and results of coagulation studies were normal. Serum and cerebrospinal α1-fetoprotein levels were markedly elevated at 7555 µg/L and 1028 µg/L, respectively. Serum quantitative human chorionic gonadotropin levels were in the normal range. Magnetic resonance imaging of the head (Figure 1) showed a multicystic mass located within the third ventricle.
The patient developed seizures on the third day of life and underwent radical resection of the intracranial mass on the following day. A 4-cm, grayish, heterogeneous tumor growing into the cavum septum pellucidum and third ventricle was resected. The surgical specimen consisted of 3 pieces of soft, tan and maroon, gelatinous tissue. Microscopic sections of the tumor are shown in Figure 2 and Figure 3.