Bilateral tonsillar adenoid cystic carcinoma.

Adenoid cystic carcinoma is a malignant epithelial tumor of the salivary glands. It accounts for less than 1% of all head and neck cancers and less than 10% of all salivary gland neoplasms. It shows slow and indolent growth rate, low probability of regional nodal metastases, high propensity for perineural invasion, multiple and/or delayed recurrences and high incidence of distant metastases. It is the most frequently encountered malignant tumor of the minor salivary glands. The oral cavity and the oropharynx are the most common sites followed by the parotid, submandibular gland, paranasal sinuses, larynx, trachea, and pharynx, in frequency order. In this report an adenoid cystic carcinoma of oral cavity localized in the left palatine tonsil and right peritonsillar tissue was presented.