A Case of Giant Cervical Cystic Mass in the Neck of a Neonate.

We report a case of a 1-day-old female neonate presenting with a prenatal ultrasound-detected 12-week-old left neck mass causing respiratory distress. Prenatal ultrasound revealed a 3.3 × 1.8 × 0.9 cm cystic mass posterior-lateral to the left thyroid lobe, anterior to the common carotid artery, with poor sonic transmission and floating echogenic particles. During the surgical procedure, we found the cyst embedded between the sternocleidomastoid muscle, cervical sheath, and trachea, adherent to surrounding tissues. Histopathology confirmed a thyroglossal duct cyst (TDC). Postoperative recovery was uneventful with no recurrences at 6-month follow-up.