Prenatal sonographic diagnosis of dilated cavum vergae

Several cases of enlarged cavum vergae have been reported, but prenatal diagnosis of this condition is very rare. We report 3 cases of dilated cavum vergae diagnosed prenatally using sonography. In 1 of the 3 fetuses, ventriculomegaly and lumbar meningomyelocele were additional sonographic findings. In 1 of the 3 infants, a stereotactic cyst–peritoneal shunt was placed at 6 months of age to relieve intracranial hypertension due to progressive enlargement of the cavum vergae. The infant who had a meningomyelocele required surgical repair of this defect shortly after birth; in the third infant, the dilated cavum vergae remained asymptomatic, and no surgery was necessary. When interhemispheric cystic lesions are identified prenatally, physicians must distinguish them from pathologic cysts and determine whether associated malformations are present. Sonography is useful for both the differential diagnosis and identification of associated anomalies. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:378–383, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jcu.10083