Choroid plexus cysts – transient element or a predictor factor?

Introduction. The choroid plexus, or plica choroidea, is a plexus of cells that arise from tela choroidea in each of the ventricles of the brain. Regions of the choroid plexus produce and secrete most of the cerebrospinal fluid of the central nervous system. The prevalence of choroid plexus cyst (CPC) is 1:50 fetuses at 20 weeks of gestation and more than 90% resolve by 26 weeks, usually being asymptomatic, but large cysts can cause hydrocephalus. Ultrasound diagnosis is characterized by single or multiple cystic areas (>2 mm in diameter) in one or both choroid plexuses of the lateral cerebral ventricles in biparietal diameter section. The differential diagnosis should exclude an intraventricular hemorrhage penetrating into the choroid plexus and other rare types of cysts like colloid or ependymal cysts. Methodology. We compared two cases of fetuses with CPC, the first one being a fetus with aneuploidy and a series of anomalies detected at the ultrasound examination (intracardiac echogenic focus, increased nuchal fold and absent nasal bone), and the second one being a fetus with normal karyotype where CPC represented a transitory factor. Results. Choroid plexus cysts, also called “soft signs”, are associated with a risk for trisomy 18 and, possibly, trisomy 21. When they are isolated, the risk for aneuploidy is low. If they are present, a detailed ultrasound examination should be performed, with particular attention to the heart, brain and hands. If the ultrasound is abnormal, the next step should be a noninvasive prenatal test (NIPT) to determine the fetal karyotype. Conclusions. In the vast majority of cases, CPC are benign transient variants of normal intracranial anatomy. Chromosomal studies are strongly recommended whenever associated anatomic abnormalities are detected and when choroid plexus cysts are large, bilateral and persistent. [ABSTRACT FROM AUTHOR]