First bite syndrome caused by adenoid cystic carcinoma of the submandibular gland.

First bite syndrome is a well-described sequelae of parapharyngeal space surgery, thought to result from sympathetic denervation of the parotid gland. We describe a case of first bite syndrome caused by an adenoid cystic carcinoma of the submandibular gland. The tumor was not clinically or radiographically apparent until 18 months after initial presentation despite repeated imaging. In patients with first bite syndrome and no surgical history, there must be high suspicion for a malignancy, which may be occult on presentation. The submandibular gland should be considered as a possible site of a lesion.