Papillary cystadenoma lymphomatosum (Warthin's tumour).

Papillary cystadenoma lymphomatosum (Warthin tumor, adenolymphoma) is a benign salivary gland tumor that occurs almost exclusively in the parotid gland. It represents 5 to 6% of all salivary gland tumors, and it is the second most common benign parotid neoplasm. Men are affected more often than women, usually in the fifth to seventh decades of life, although this gender proportion is changing. Warthin tumor is associated with smoking. The most common clinical manifestation is a painless, slowly growing mass in the inferior pole of the superficial lobe of the parotid gland, usually at the level of the mandibular angle. Multifocality occurs in up to 14% of cases; when two salivary gland neoplasms are present synchronously, Warthin tumor is the most common second tumor.