RESUMEN
Carcinoma arising from the remnant of branchial epithelium or branchial cleft cyst is known as branchiogenic carcinoma. It is very rare, and its existence is a matter of controversy. We report a case of cystic carcinoma of the upper neck that fully met Martin's criteria for branchiogenic carcinoma. A 53-year-old male visited Tsurumi University Dental Hospital with a swelling on the left side of the neck. Three tumors were excised from the neck, and histopathology revealed squamous cell carcinoma in a cystic lesion. As metastatic carcinoma of the cervical lymph nodes was suspected, the appropriate clinical tests and imaging were performed to determine the possible presence of a primary tumor. However, no primary carcinoma was found. These findings suggest that this was a case of branchiogenic carcinoma. The patient was treated with radiotherapy and followed up over an 8-year period. No evidence of recurrence was found.