A 6-month-old infant has a large, soft, compressible swelling in the left posterior triangle of the neck present since birth. It is multiloculated on ultrasound and brilliantly transilluminates. The swelling enlarges when the child cries. Most likely diagnosis?

• A Branchial cyst
• B Haemangioma
• C Thyroglossal duct cyst
• D Cystic hygroma ✓

Explanation

Cystic hygroma is a congenital lymphatic malformation arising from sequestration of lymphatic tissue, classically located in the posterior triangle of the neck in infants. It is soft, lobulated, compressible, transilluminates brilliantly because of clear lymph fluid, and may enlarge with crying due to increased venous pressure. Branchial cysts occur later in life in the anterior triangle, thyroglossal cysts are midline, and haemangiomas are vascular rather than lymphatic lesions.

Reference: Diseases of Ear, Nose and Throat (Dhingra), 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.