Two-year follow-up of a rare primary branchial cleft carcinoma: Case analysis and management insights.

Branchial cleft cysts are congenital anomalies of development, with the second branchial cleft cyst being the most common clinically. In extremely rare cases, branchial cleft cysts can undergo malignant transformation. Herein, we present a rare case of a 65-year-old male patient who had a painless neck mass on the left side for 6 months.