SIGNIFICANCE OF SONOGRAPHICALLY DETECTED 2ND-TRIMESTER CHOROID-PLEXUSCYSTS - A SERIES OF 211 CASES AND A REVIEW OF THE LITERATURE

A retrospective analysis of all fetuses with prenatally detected choro id plexus cysts, identified at our institution between 1988 and 1993, was performed. Cytogenetic data, associated sonographic findings, obst etric outcome and pediatric follow-up was obtained to determine the in cidence of aneuploidy and the rate of associated congenital anomalies in second-trimester fetuses with this finding. There were 211 second-t rimester fetuses identified with a choroid plexus cyst. Amniocentesis was performed in 175 (83%) and postnatal chromosome analysis was perfo rmed in one newborn. Follow-up data are available on 203 (96%). Of the 176 cytogenetically studied fetuses, eight (4.5%) were aneuploid (inc luding four cases of trisomy 18). In four of the aneuploid fetuses, th e choroid plexus cyst was the only abnormal sonographic finding identi fied (including one case of trisomy 18). From this study and a review of the literature, we confirm that choroid plexus cysts are a sonograp hic marker for trisomy 18, even when identified as an isolated finding in an otherwise normal-appearing fetus. We conclude that the detectio n of a choroid plexus cyst merits further careful evaluation of fetal anatomy and consideration of cytogenetic evaluation.