Prenatal and postnatal evolution of isolated fetal splenic cysts

The aim of this study was to evaluate the prevalence, the prenatal, and postnatal evolution of isolated fetal splenic cysts.

All cases of suspected fetal splenic cyst or abdominal unidentified cyst discovered during routine ultrasound scan, from 2007 to 2017, and referred to a French tertiary care center, were retrospectively collected. For each case, several prenatal parameters and postnatal evolution were reported.

Among 5450 cases of fetal anomalies, 14 patients (0.3%) had a prenatal diagnosis of fetal splenic cysts. Median gestational age at diagnosis was 30.1 weeks. A unique cyst was present in 78.6%, whereas 2 cysts were observed in 14.3% and 3 cysts in 7.1%. During the pregnancy, cysts remained the same (78.6%) or disappeared (21.4%). Ultrasound scans at 6 months of age found total disappearance of the cysts (36.4%), spontaneous reduction from 2 to 1 cyst (18.2%) or persistence of the cysts (45.4%).

Fetal splenic cysts are rare images, always isolated, usually unique and mainly found during third trimester of pregnancy. Their evolution is to disappear spontaneously during pregnancy or at 6 months of age leaving only half of them to remain beyond that age but without any symptoms.