Pleomorphic adenoma with mucinous and squamous differentiation: a mimicker of mucoepidermoid carcinoma.

Pleomorphic adenoma with foci of squamous and mucinous differentiation can potentially be misdiagnosed as low-grade mucoepidermoid carcinoma. The circumscribed borders of the tumor, gradual merging of mucoepidermoid foci into areas typical of pleomorphic adenoma, and presence of keratinization are features against the latter diagnosis.