<prompt> The commonest tumour of parotid isMucoepidermoidMixed parotid tumourAdenolymphomaSquamous cell carcinoma  <response>: Pleomorphic adenomas are benign tumors that consist of a mixture of ductal epithelial and myoepithelial cells, and therefore they show both epithelial and mesenchymal differentiation. Because of their remarkable histologic diversity, these neoplasms have also been called mixed tumors. They represent about 60 of tumors in the parotid. Wahin tumor is the second most common. Both are benign. Robbins 9e pg: 745 