Papillary and verrucous lesions of the oral mucosa

A variety of verrucous and papillary lesions affect the oral mucosa. Those which are benign and reactive, for example squamous papilloma or verruciform xanthoma, usually present little diagnostic difficulty. However, dysplastic and malignant verrucous and papillary lesions are a much greater diagnostic challenge, not helped by confusing terminology. Papillary hyperplasia is a reactive inflammatory condition, whereas verrucous hyperplasia is a potentially malignant dysplasia, and probably part of the spectrum of verrucous carcinoma. Papillary carcinomas, at least in the oral context, are essentially verrucous hyperplasias. ‘Oral florid papillomatosis’ is an obsolete term synonymous with verrucous carcinoma. A ‘classical’ verrucous carcinoma, with an exo-/endo-phytic growth pattern, ‘pushing’ invasive front and intact basement membrane, is easily identified, but many exophytic verrucous hyperplasias also show endophytic growth. These can also reasonably be diagnosed as verrucous carcinoma. If the lesion shows more than focal, early invasive disruption of the basement membrane, it should be diagnosed as a conventional squamous cell carcinoma.