Congenital periventricular pseudocysts: prenatal sonographic appearance and clinical implications

Periventricular pseudocysts (PVPC) are diagnosed in approximately 1% of premature newborns that undergo brain sonography during the first 24 h of life. These pseudocysts are thought to develop antenatally due to germinal matrix hemorrhage, but have not been described until now in prenatal ultrasound studies. The aim of this study was to report the identification, differential diagnosis, and prognosis of PVPC detected by prenatal ultrasound examination.

Between 1997 and 2001 we made an ultrasound diagnosis of PVPC in 11 fetuses. In nine fetuses the findings were characteristic of PVPC and these patients represent our study group. Fetal magnetic resonance imaging was performed in five patients. Termination of pregnancy was carried out in three patients, in one case intrauterine fetal death occurred at 31 weeks, and one infant died in the neonatal period. The surviving four newborns are being followed in the pediatric neurology clinic.

PVPC were diagnosed by ultrasound scan in fetuses between 16 and 37 weeks of gestation (mean, 29.7 weeks). Magnetic resonance imaging confirmed the presence of PVPC in two cases. In eight cases the pseudocysts were unilateral and in one case bilateral. They were an isolated finding in five patients. Four of these fetuses were delivered at term and have normal neurological development at ages ranging from 6 to 25 months. All fetuses with additional pathologies (coarctation of the aorta, hemimegalencephaly, cytomegalovirus infection, hypoplasia of the vermis with dysmorphism) did not survive.

The prenatal diagnosis of PVPC warrants an extensive search for possible associated pathological findings. As an isolated finding, antenatal PVPC seem to carry a good prognosis.