p16INK4A immunohistochemical staining may be helpful in distinguishing branchial cleft cysts from cystic squamous cell carcinomas originating in the oropharynx
Carcinoma, Squamous Cell
Cyclin-Dependent Kinase Inhibitor p16
Head and Neck Neoplasms
Branchial cleft cysts can exhibit focal strong reactivity limited to the superficial squamous epithelium and glandular epithelium. Although p16(INK4A) immunohistochemistry may be helpful in distinguishing oropharyngeal nonkeratinizing SCC from branchial cleft cysts in FNAB specimens, it is not helpful in cases of keratinizing SCC because these cases are typically negative for p16(INK4A).