Palatal pleomorphic adenoma with florid squamous metaplasia: a potential diagnostic pitfall

We report a case of pleomorphic adenoma with extensive squamous metaplasia in the palate of a 52-year-old Chinese man. The dimensions of the tumor were 15 x 13 x 13 mm. More than 95% of the epithelial element in the tumor was composed of sheets of squamous cells with cyst formation. The pathogenesis, potential diagnostic pitfalls, proliferative activity and cytokeratin expression of this tumor are discussed.