Proliferative verrucous leukoplakia: a proposal for diagnostic criteria.

Proliferative verrucous leukoplakia (PVL) is a rare form of oral leukoplakia, which was first described in 1985 by Hansen et al. Since then, various published case series have presented PVL as a disease with aggressive biological behaviour due to its high probability of recurrence and a high rate of malignant transformation, usually higher than 70%. PVL is a long-term progressive condition, which is observed more frequently in women and elderly patients over 60 years at the time of diagnosis. Eventually, PVL tends to become multifocal with a progressive deterioration of the lesions, making it more and more difficult to control. Tobacco use does not seem to have a significant influence on the appearance or progression of PVL. These lesions may occur both in smokers and non-smokers. Nevertheless, at present, the aetiology of PVL remains unclear as well as its management and diagnosis, which is still retrospective, late and poorly defined, lacking consensus criteria. Therefore, the aim of this study is to propose a set of diagnostic criteria to allow for the early and objective identification of PVL cases, and thereby conduct an adequate management. The proposal includes five major criteria and four minor criteria, as well as specific combinations among them in order to establish a correct and objective diagnosis of proliferative verrucous leukoplakia.