Pleomorphic adenoma (50%)
Warthin tumor (5%-10%)
Oncocytoma (1%)
Other adenomas (5%-10%)
Basal cell adenoma
Canalicular adenoma
Ductal papillomas
Warthin's: b9, parotid, males 50-70 who smoke, classic histol: cystic spaces separate lobules of neoplastic epithelium consisting of a double layer of eosinophilic epithelial cells based on a reactive lymphoid stroma
Pleomorphic adenoma: 80% of b9 salivary tumors, 85% parotid but all other salivary sometimes, epithelial and myoepithelial cells in chondroid matrix
**Malignant**
Mucoepidermoid carcinoma (15%)
Adenocarcinoma (NOS) (10%)
Acinic cell carcinoma (5%)
Adenoid cystic carcinoma (5%)
Malignant mixed tumor (3%-5%)
Squamous cell carcinoma (1%)
Other carcinomas (2%)
Mucoepidermoid: biopsy of salivary gland tumor shows islands with squamous cells as well as clear cells containing mucin.
-- a distinct type of tumor w/ 3 cellular elements in varying proportions: squamous cells, mucus-secreting cells, and "intermediate" cells, well recognized as a common salivary gland neoplasm, accounting for approximately 35% of all malignancies of the major and minor salivary glands in general. Mucoepidermoid carcinomas have been reported at distant and atypical sites, including the breast, Eustachian tube of the ear, bronchi of the lungs, and thyroid. Reports of mucoepidermoid carcinomas of the subglottis are not common. Women are more commonly affected than men (3:2), and the mean age at onset is in the 5th decade of life. MEC is also the most common salivary gland malignancy in children. http://www.oralcancerfoundation.org/facts/rare/mc/index.htm
Adenocarcinoma: malignant tumor in epithelial tissue, specifically in a gland, most common in colon, adenocarcinomas develop from adenomas. In general, the bigger the adenoma, the more likely it is to become cancerous. For example, polyps larger than two centimeters (about the diameter of a nickel) have a 30-50 percent chance of being cancerous, Two subtypes of adenocarcinoma include signet ring cell adenocarcinoma and mucinous adenocarcinoma. Signet ring cell adenocarcinoma is named for the way its cells look under a microscope. Mucinous adenocarcinoma is referred to as "mucinous" because its cells contain so much mucus.