A patient has an injury in the submandibular region/triangle of the neck with pain that worsens when eating and swallowing. What is the most likely diagnosis?

Correct answer: B. Infection of the submandibular gland (sialadenitis)

• A. INCORRECT — Mumps (parotid gland infection) affects the parotid gland (pre-auricular), not the submandibular region, and causes bilateral swelling.
• B. CORRECT — Submandibular sialadenitis (often with salivary calculi/sialolithiasis) classically presents with pain in the submandibular region that is exacerbated at mealtimes when salivary flow increases, causing obstruction-related pressure and pain.
• C. INCORRECT — Branchial cleft cysts occur along the anterior border of the sternocleidomastoid and are typically soft, painless masses unless infected.
• D. INCORRECT — Thyroglossal duct cysts are midline neck masses that move with swallowing and tongue protrusion; they are not typically associated with pain worsening on eating.