Pathology · single question
A patient has a nodule in the anterior portion of the sternocleidomastoid muscle region of the neck. What is the most likely differential diagnosis?
Show answer and explanation
Correct answer: A. Branchial cleft cyst
- A. CORRECT — A branchial cleft cyst (also called branchial cyst) classically presents as a soft, non-tender mass along the anterior border of the sternocleidomastoid muscle, typically in the upper neck. It is a remnant of the second branchial arch/cleft and is the most common neck cyst in adults.
- B. INCORRECT — Lymphoma can present as cervical lymphadenopathy but typically involves multiple nodes and is harder/fixed rather than soft and fluctuant.
- C. INCORRECT — Thyroglossal duct cysts are MIDLINE neck masses that move with swallowing and tongue protrusion; they are not found along the sternocleidomastoid.
- D. INCORRECT — Lipomas are soft, mobile, non-tender subcutaneous masses but are not specifically located along the sternocleidomastoid and do not have the embryological origin that makes branchial cleft cyst the classic diagnosis here.