Mucoepidermoid carcinoma in a cervical cyst: a case of branchiogenic carcinoma?

A patient with a primary oral epidermoid carcinoma with presumed neck metastasis is presented who at operation was found to have a cervical mucoepidermoid carcinoma arising in the wall of a benign cyst. The case for considering this tumor a primary branchioma of mucoepidermoid type is presented, and the criteria for making the diagnosis of branchiogenic carcinoma are discussed.