Prenatal pseudocysts of the germinal matrix in preterm infants.

Sonographic characteristics of germinal-matrix (PGM) pseudocysts of prenatal origin detected on cranial ultrasound in preterm newborns were correlated with their outcomes. PGM cysts were classified as typical or atypical, according to their location. Typical PGM cysts were present at the head of the caudate nucleus or slightly medially, adjacent to the foramen of Monro. Cysts were defined as atypical when they were located subependymally elsewhere. Only one infant of 16 with a typical PGM cyst presented with psychomotor retardation. His cerebral scan also showed subependymal calcifications due to cytomegalovirus infection. Three babies had cysts in the frontal periventricular zones (atypical PGM cyst). They had negative cranial MRI (12-15 months of age) and normal neurological follow-up (24 months). In conclusion, isolated prenatal PGM cysts in preterm infants correlate with a normal outcome.