W. Adrian Clavelli, MD

CEMIC fetal treatment center *Dept of Ultrasound, Buenos Aires, Argentina

This is a 3rd trimester fetus with an arachnoid cysts. Note the large irregular cystic collection that does not extend to the skull (differential diagnosis with schizencephaly). No flow in the cyst (differential diagnosis with a vein of Galen aneurysm). The cyst was shunted postnatally.