A 30-year-old presents with a painless fluctuant swelling at the anterior border of the sternocleidomastoid muscle at the junction of its upper and middle thirds. The swelling transilluminates. The most likely diagnosis is:

• A Lymph node abscess
• B Thyroglossal cyst
• C Second branchial cleft cyst ✓
• D First branchial cleft cyst

Explanation

Second branchial cleft cysts are the most common branchial anomalies. They typically present as smooth, fluctuant swellings along the anterior border of the sternocleidomastoid at the junction of upper and middle thirds. They may transilluminate when cystic. The sinus (if present) opens at the anterior SCM border in the neck. They are lined by squamous or columnar epithelium and contain cholesterol crystals. Thyroglossal cysts are midline and move with tongue protrusion. First branchial cysts are in the parotid or periauricular region.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.