Euploid First-Trimester Cystic Hygroma: A More Benign Entity than Previously Thought?

Outcome of Sclerotherapy in a Preterm Infant with a Giant Fetal Neck Lymphatic Malformation: A Case Report

Introduction

Lymphatic malformation (LM), most commonly present in the neck area, is benign vascular malformations of the lymphatic system. In an infant, however, LM poses a high risk of adverse outcomes.

Case Presentation

We present a case with a giant fetal LM. Through ultrasonography, at 23+ weeks of gestation, a septate cystic mass 7.2×6.5×6.3 cm in size was found on the right side of the fetus's neck. After extensive counseling by the multidisciplinary team, the parents chose to continue the pregnancy. Severe fetal tracheal compression was observed at 29 weeks by magnetic resonance imaging (MRI). At 31 weeks and 5 days, owing to suspected fetal distress, an emergency cesarean section was performed and a male baby weighing 1720 g was delivered. The mass was 10×16×8 cm in size and ex utero intrapartum treatment (EXIT) was implemented. Due to progressive growth of the mass secondary to intralesional bleeding, an intralesional injection of bleomycin was administered three days later. This injection was repeated at the age of 1 month and 8 days. The baby was followed up and, by a year after his birth, LM had disappeared. The baby has since been in good health.

Conclusion

Accurate prenatal diagnosis and regular monitoring of a fetus with LM may improve prognosis. It is essential to have a trained multidisciplinary team to evaluate the condition of the fetus and the neonate and to provide treatment based on the evaluation. Our experience with intralesional bleomycin injection for the treatment of a giant fetal neck LM in a preterm infant had a favorable outcome. Long-term follow-up by a multidisciplinary team is needed in such cases.

Current Perspectives of Prenatal Cell-free DNA Screening in Clinical Management of First-Trimester Septated Cystic Hygroma

First-trimester septated cystic hygroma occurs in approximately 1 in 268 pregnancies and has long been associated with a markedly increased risk of fetal aneuploidy and, among euploid fetuses, an increased risk of structural anomalies primarily affecting the cardiac and skeletal systems. Invasive prenatal diagnosis – chorionic villus sampling and/or amniocentesis – encompasses the time-honored clinical tools for the next step in management following prenatal sonographic diagnosis of first-trimester septated cystic hygroma. Currently, prenatal cell-free DNA (cfDNA) screening for fetal aneuploidy with select microdeletions is gradually replacing the considerably less sensitive, and labor-intensive combined first-trimester screening. These new technologies have opened potential new venues in the clinical management of this ominous late first-trimester sonographic diagnosis. Advances in cfDNA technologies are now permitting detection of chromosomal copy number variants (CNV) larger than 7Mb across genome and select serious single-gene disorders (mainly impacting skeletal and neurological development), affecting quality of life and may benefit from medical and/or surgical management. This commentary will address the available non-invasive prenatal screening technologies, which clearly enhance immediate genetic analysis modalities applicable in the presence of the complex sonographic finding of first-trimester septated cystic hygroma.