placental venous lake
Placental
lake • Placental lakes - Ganzer Fall bei Radiopaedia
Placental (venous) lakes refer to a phenomenon of formation of hypoechoic cystic spaces centrally within the placenta. Finding placental lakes during a second trimester ultrasound scan is not associated with any uteroplacental complication or with an adverse pregnancy outcome. They can, however, be abnormal if very diffuse or if seen very early in pregnancy.
Epidemiology
Placental lakes are a common occurrence, reported to occur in approximately 20% of pregnancies.
Associations
Their presence tends to be associated with:
- increased placental thickness
- placenta accreta spectrum and abnormal placental villous adherence
- placental insufficiency, especially if seen early in pregnancy
Pathology
They usually result from perivillous fibrin deposition with cystic change within areas of subchorionic fibrin.
Markers
- the presence of placental lakes is associated with increased maternal serum alpha-fetoprotein (MSAFP) levels
Radiographic features
Antenatal ultrasound
- relatively well defined hypoechoic regions within the placenta
- color Doppler imaging may show low-velocity intraplacental laminar flow
Differential diagnosis
- placental chorioangioma: shows marked internal vascularity on color Doppler imaging
Siehe auch:
- Plazentainsuffizienz
- abnormal placental villous adherence
- placenta accreta spectrum
- increased maternal serum alphe-feto protein (MSAFP)