Benign papillary squamous tumors of the mouth.

Sixty-eight cases of benign papillary squamous tumors of the mouth were reviewed to elucidate further their histopathologic variations, as well as to clarify the premalignant nature of these tumors. The cases were classified into five varieties: idiopathic pseudoepitheliomatous hyperplasia (2 cases), papilloma (55 cases), oral florid papilloma (7 cases), inverted papilloma (3 cases) and recurring oral papillomatosis (1 case). The series included very rare cases, to our knowledge, undescribed in the literature. Though a microscopic differentiation between the benign papillary squamous tumors, verrucous carcinoma and well differentiated squamous cell carcinoma is quite difficult, clinical and pathologic recognition of these tumors is imperative, because of the differences in their clinical course and therapeutic requirement. A definite diagnosis should be made after the clinical and microscopic findings have been carefully correlated. Malignant change occurred in the oral florid papilloma and recurring oral papillomatosis.