Cystic hygroma is a congenital lymphatic malformation frequently diagnosed during first-trimester ultrasound screenings. This anomaly, characterized by cystic masses typically found in the cervical and thoracic regions, poses significant challenges due to its association with chromosomal abnormalities, notably trisomy 21. We present a case study of a 32-year-old primigravida at 11 weeks of gestation diagnosed with a cervico-thoracic cystic hygroma measuring 4.5 mm in nuchal thickness, confirmed by Doppler ultrasound. Karyotyping revealed trisomy 21, prompting the decision for fetal termination. Discussion focuses on the clinical implications of cystic hygroma, emphasizing its poor perinatal prognosis and the importance of early detection and cytogenetic analysis in managing pregnancies affected by this condition. Understanding the ultrasound characteristics and prognostic factors associated with cystic hygroma is crucial for appropriate prenatal counseling and management strategies.
