Oral proliferative verrucous leucoplakia: are there particular features for such an ambiguous entity? A systematic review

Proliferative verrucous leucoplakia (PVL) is a distinct, particularly aggressive form of oral leucoplakia. Given the low prevalence of PVL, data are sparse and are mostly from case reports, case series and only a few case-control studies, meaning that the literature is able to provide only weak evidence. The present systematic literature review aims to collate the available evidence on the following issues: patient demographics, aetiology, lesion location(s), malignant potential, location and histopathological features of transformed lesions, disease-specific survival rates and treatment response. Electronic databases were searched for studies in the English language reporting original data from at least 10 patients with PVL on the target issues of the present review. The retrieved data were merged and a descriptive analysis performed. The 20 studies selected indicated that PVL does not seem to be correlated with the major risk factors for oral carcinoma (tobacco, alcohol and/or areca nut/betel leaf chewing). The disorder affects mainly adult/elderly women and has a very high malignant transformation rate, particular site distribution and particular location and histopathological features of transformed lesions. The present results may be limited by some articles being unintentionally excluded as they were not found during the electronic search, a lack of worldwide accepted diagnostic criteria for PVL, and overlapping data from multiple studies performed in a limited number of centres. Despite these potential drawbacks, the present results demonstrate that PVL does have particular features.