The significance of anterolateral neck cysts in early diagnosis of fetal malformations

Objective The objective of this study is to examine the association of lateral fetal neck cysts with increased nuchal translucency, chromosomal abnormalities and fetal malformations. Method In a consecutive collective of 4216 prenatal ultrasound examinations between 11 and 17 weeks of gestation 32 fetuses with lateral neck cysts were found. The size of the cysts was examined. The association of the findings with increased nuchal translucency, chromosomal aberrations and fetal malformations was examined. Results All but two out of 32 cases had bilateral cysts. Seventeen fetuses had aneuploidy and an increased nuchal translucency, 15 of those with major structural malformations. Of the 15 fetuses with normal karyotype nine (60%) had an increased nuchal translucency, seven had a fetal malformation or hydrops. A favorable outcome was found in 6/15 fetuses with normal karyotype and normal nuchal translucency. Lateral neck cyst diameter was associated to nuchal translucency, chromosomal abnormality and/or fetal malformations. Cysts smaller than 3 mm had a favorable outcome even in the presence of an increased nuchal translucency. Conclusion Fetuses with lateral neck cysts often not only present with increased nuchal translucency and chromosomal aberrations but also with fetal malformations. Fetuses with lateral neck cysts and increased nuchal translucency were aneuploid or had a fetal malformation in 85%. Cysts smaller than 3 mm had a favorable outcome. © 2016 John Wiley & Sons, Ltd. What's Already Known About This Topic? There is an association between lateral neck cysts, increased nuchal translucency and fetal aneuploidy. What Does This Study Add? Fetuses with lateral neck cysts in combination with increased nuchal translucency showed a significant risk for aneuploidy and structural malformations compared with euploid fetuses. Further cysts smaller than 3 mm have a favorable outcome regardless of the nuchal translucency.