Prenatal diagnosis of frontal encephalocele

A 28-year-old G II P II patient was referred to our materno-fetal medicine department, after routine dating ultrasound, revealing protrusion of a cerebral mass through a bony defect of skull. The patient had no prenatal care prior to this time and was 20 weeks of gestational by dates. The family history was negative for congenital anomalies or genetic abnormalities and the patient denied exposure to drugs or toxins. Our ultrasound examination revealed a single fetus with femur length measurement adequate with 20 weeks gestational age. The diagnosis of encephalocele was easy because a large paracranial mass was seen at ultrasonography. The presence of brain tissue inside de sac confirmed our diagnosis. Because encephalocele is often associated with other anomalies, we careful investigated the entire fetal anatomy, but we found nothing else.

The umbilical cord and placenta were normal in appearance and location. Because it was a malformation incompatible with postnatal life, after counseling, the parents have decided upon therapeutical abortion.

The infant was male, dead during abortion. The results of autopsy confirmed pathological findings detected by ultrasound; the placenta and umbilical cord were unremarkable. Parental karyotyping was recommended, but the both were normally.

We present this case because frontal encephalocele is relative rare: 12% of cases. When is isolated, there is no genetic determination and recurrences are rare.