Adenoid cystic carcinoma of the parotid gland associated with salivary calculi: An unusual presentation.

Adenoid cystic carcinomas (ACC) of the head and neck are relatively rare tumors, consisting of approximately 10-15% of all salivary gland neoplasms. ACC, a slow-growing aggressive malignant tumor of salivary gland commonly seen in the submandibular, sublingual, minor salivary glands is seldom found in the parotid. Calculus, the common cause of salivary gland dysfunction is usually identified in submandibular salivary gland because of its duct anatomy and physiochemical characteristic serous secretion. We report an unusual case of co-existent presentation of ACC with salivary calculi in the parotid gland which is never been reported in the literature. Co-existence of ductal calculi and ACC is rare. Presence of parotid calculus could be due to long standing ductal obstruction by the slow-growing ACC of the parotid or other possibility is that the malignancy could have developed because of chronic irritation by parotid calculi. Confirmatory studies are required to understand its mutual pathological association.