Fetal lateral neck cysts: The significance of associated findings

Objectives: The detection of fetal lateral neck cysts (FLNC) may create anxiety and confusion among pregnant woman and their physicians. We attempted to determine the incidence and significance of FLNC. Also, we tried to define the importance of the associated findings: the laterality of the finding, triple test results, maternal age and other ultrasonographic findings. Methods and Materials: Between January 2000 and September 2003, 80 fetuses were evaluated at our institution for FLNC out of 3350 ultrasonic scans done for fetal malformations at 14-16 weeks' gestation. Results: The incidence of FLNC was 2.4% (80/3350). The majority of cases were isolated (53/80, 66%) and unilateral (46/80,58%). Down syndrome was associated with nonisolated FLNC. Conclusion: Whether the finding was unilateral or bilateral had no significance. Associated increased nuchal translucency (NT) was of importance. Furthermore, the sole finding of increased NT is significant and the finding of the FLNC has no added value. There was no correlation between isolated FLNC without NT and fetal aneuploidy. However, other risk factors increase the risk for aneuploidy by up to 15 fold.