Cystic metastasis from occult tonsillar primary simulating branchiogenic carcinoma: the case for tonsillectomy as a "grand biopsy".

The occult primary is a problem well known to head and neck surgeons. Less frequently discussed, but well documented, is cystic degeneration of metastatic nodes. When these conditions combine, they can suggest tumor arising in a pre-existing cervical cyst. This is a controversial condition, rare if it occurs at all, and is not to be invoked lightly.