On MRI neck with contrast, a cystic mass at the angle of the jaw in a 35-year-old presents with a tract to the skin externally and to the tonsillar fossa internally. This is most consistent with:

• A First branchial cleft cyst (Work type II)
• B Second branchial cleft cyst/fistula (Bailey type II) ✓
• C Thyroglossal duct cyst with lateral ectopic thyroid
• D Ranula with plunging extension through the mylohyoid

Explanation

Second branchial cleft anomalies (Bailey classification) are the most common branchial apparatus anomalies. A complete second branchial fistula opens externally at the anterior border of the lower sternocleidomastoid (skin dimple) and internally at the tonsillar fossa, passing between the external and internal carotid arteries and lateral to CN IX and XII. Bailey type II (most common) has its cystic component at the angle of the mandible deep to SCM. First branchial cleft anomalies are near the EAC/parotid. Thyroglossal duct cysts are midline, moving with swallowing/tongue protrusion. Plunging ranula arises from sublingual gland.

Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.