Primary branchiogenic carcinoma: malignant degeneration of a branchial cyst, a case report.

Background: Primary branchiogenic carcinoma (PBC) is an extremely rare and poorly documented disease developed from a brachial cleft cyst.

Case: A 51-year-old patient was referred to our unit for an upper neck mass. PBC was confirmed in accordance with Kahfif's diagnostic criteria. Prophylactic selective neck dissection was performed in a second-stage surgery to ensure the complete removal of the neoplasm. Branchiogenic origin with lymphoid tissue was confirmed in the "host cyst" after histological examination and no other tumors were found elsewhere. Regular follow up documented no relapse 12 months after surgery.

Conclusions: Although rare, PBC must be suspected in presence of cervical masses, especially in patients older than 40 years. A standardized treatment algorithm still lacks, but prophylactic selective neck dissection could be considered as the first line choice after the diagnosis has been confirmed.