Management of Choroid Plexus Cysts on Fetal Anatomy Ultrasound

Understanding Choroid Plexus Cysts

Choroid plexus cysts (CPCs) are small, fluid-filled structures within the choroid of the lateral ventricles of the fetal brain, appearing as echolucent cysts within the echogenic choroid 1
They may be single or multiple, unilateral or bilateral, and typically measure <1 cm in diameter 1
Nearly all CPCs resolve spontaneously by 28 weeks gestation 1, 3
CPCs are not considered structural or functional brain abnormalities 1

CPCs are associated with trisomy 18, present in 30-50% of fetuses with this disorder 1
When a fetus has trisomy 18, multiple structural anomalies are almost always evident (structural heart defects, clenched hands, talipes deformity, FGR, polyhydramnios) 1
The presence of a CPC does not alter the risk of trisomy 21 1
For isolated CPCs (without other abnormalities), the likelihood ratio for trisomy 18 is <2, suggesting minimal risk 1

The American College of Obstetricians and Gynecologists recommends that for patients with no previous aneuploidy screening, a detailed ultrasound should be performed to confirm the CPC is truly isolated, and the patient should be counseled regarding the minimal increased risk of trisomy 18 1, 4, 5
The American College of Obstetricians and Gynecologists recommends offering noninvasive aneuploidy screening with cell-free DNA (cfDNA) or quad screen if cfDNA is unavailable or cost-prohibitive 1, 6
Invasive diagnostic testing (amniocentesis) is not recommended solely for isolated CPCs 1, 6

Overreaction to isolated CPCs can lead to unnecessary procedure risks, and the American College of Obstetricians and Gynecologists recommends against recommending invasive testing solely for isolated CPCs 1
Unnecessary follow-up imaging is not needed for isolated CPCs when aneuploidy screening is negative, as stated by the American College of Obstetricians and Gynecologists 1, 6
Failure to distinguish between isolated and non-isolated CPCs can lead to incorrect risk assessment, and the American College of Obstetricians and Gynecologists recommends considering the presence of other structural abnormalities when evaluating the risk of trisomy 18 1