A 41 year old man presented with swelling over parotid area. He has only mild pain. Which is the commonest tumor of the parotid?

Pleomorphic adenomas or benign mixed tumors, are the most common neoplasms of the salivary glands. They represent approximately 60-70% of all parotid tumors and 90% of submandibular benign tumors. These neoplasms affect females more than males and are commonly seen in the third to sixth decades of life. Histologically, pleomorphic adenomas arise from the distal poions of the salivary ducts, including the intercalated ducts and acini.