Ultrasound department of Kharkiv Regional Perinatal Center. Kharkiv Medical Academy of postgraduated education, Ukraine.

Case report

A 26-year-old woman (G1P1) was seen in our center at 27 weeks. Her 1st and 2nd trimester ultrasounds were normal. 

Our examination found a striking cystic structure located within the left fetal hemisphere of the brain. The brain structures as itself were normally developed (falx, thalami, ventricles, cerebellum etc.) but compressed by the cyst. Later the cyst had grown up to a giant size reaching nearly 77 mm in the longest diameter. Arachnoid cyst was suspected.

The newborn was delivered term via cesarean section due to macrocrania. Postnatal clinical condition of the neonate was good. MRI confirmed the findings and shunting of the cyst was performed two weeks later. The cyst had its origin in the Sylvian area of the left hemisphere. Four months after the operation the baby is doing well.

Video 1 and images 1, 2, 3, and 4: 27 weeks of gestation - striking cystic structure within the fetal brain.