A 35-year-old woman has a non-tender, firm neck swelling anterior to the sternocleidomastoid at the junction of upper and middle thirds. Ultrasound shows a cystic lesion with internal septations. FNAC reveals thin squamous cells and cholesterol crystals. The most likely diagnosis is:

• A Branchial cyst (second branchial cleft cyst) ✓
• B Lymph node metastasis from an occult primary
• C Thyroglossal duct cyst
• D Cystic hygroma (lymphatic malformation)

Explanation

A second branchial cleft cyst typically presents as a cystic neck swelling at the anterior border of the sternocleidomastoid at the junction of its upper and middle thirds — this is a pathognomonic location. FNAC showing stratified squamous lining cells and cholesterol crystals confirms the diagnosis. Thyroglossal cysts are midline and move with tongue protrusion. Cystic hygromas are multiloculated, transilluminant, and more posterior. Metastatic cystic nodes occur in older patients and require p16/HPV testing.

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.