A Case of Squamous Cell Carcinoma Arising from Branchial Cleft Cyst

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.