High magnification view of a cellular pleomorphic adenoma. The epithelial cells are arranged in acinar and trabecular patterns with mild cytologic atypia. Atypical pleomorphic adenomas show features such as anaplasia, atypical mitosis, coagulative tumor necrosis and zones of acellular hyalinization. These features might portend malignant transformation. Pleomorphic adenomas with atypical features should be sampled extensively to rule out the possibility of malignancy.