Infected Second Branchial Cleft Cyst

Axial CT image of the neck in a 2-year-old boy shows a cystic lesion in the right neck anterior to the sternocleidomastoid muscle, lateral to the carotid space. There is wall enhancement and nearby fascial thickening and subcutaneous fat stranding.

Facts: Branchial Cleft Cyst

• Type II = most common (92-99% of all branchial cleft cysts)
• Anywhere along anterior aspect of sternocleidomastoid muscle, lateral to carotid sheath to parapharyngeal space at the level of palatine tonsil
• CT: fluid density unless infected or hemorrhagic
• MRI: T1 hypointense, T2 hyperintense (unless infected or hemorrhagic)
• Can be associated with fistula or sinus tract

Other Things To Consider: Necrotic lymph node/metastasis, dermoid, abscess, laryngocele, ectopic thymic cyst

What Surgeons Want To Know

• Infection? May need surgery if at risk of septicemia or abscess
• Mass effects? Compression of esophagus, airways
• Neoplasm?
• Treatment of infected branchial cleft cyst is different from simple abscess. In the former, I&D alone is not adequate but the entire cyst and its tract must be removed to prevent recurrence. Therefore, it is important that accurate diagnosis is made preoperatively.

Our case: infected second branchial cleft cyst

Reference:

1. Bailey BJ, Calhoun KH. Atlas of Head & Neck Surgery-Otolaryngology, 2001.

2. Lin EC, Escott EJ, et al. Practical Differential Diagnosis for CT and MRI, 2008.