Proliferative Verrucous Leukoplakia: A Potentially Malignant Disorder Involving Periodontal Sites

Abstract

Proliferative verrucous leukoplakia (PVL) is a rare oral mucosa disorder, frequently involving periodontal sites, with a high rate of progression to oral squamous cell carcinoma (SCC) and verrucous carcinoma (VC). This article describes the clinical features and follow-up of a group of patients with PVL, with attention to the involvement of the mucosa covering the alveolar crest and its malignant transformation. Patients were retrospectively evaluated for demographic data, risk habits (smoking and drinking), locations of PVL lesions, incidence, and locations of malignant transformation. Patients with malignant transformation were compared to a control group (patients affected by oral carcinoma without PVL). Forty-seven patients were enrolled; PVL lesions were most frequently observed on the alveolar crest (41/47 [87.2%]), with gingival involvement in 22 of 47 (46.8%) cases. Nineteen patients (40.4%) developed 41 malignant lesions; the alveolar crest was the most affected site (12/41 [29.3%]). Compared to controls, patients with PVL were more likely to develop VC (odds ratio [OR] = 6.61; 95% confidence interval [CI]: 1.23 to 65.52) than SCC (OR = 0.15; 95% CI: 0.02 to 0.82), and they showed a higher incidence of cancer on masticatory mucosa (OR = 6.49; 95% CI: 1.78 to 29.12), particularly gingiva (P = 0.007) and the hard palate (P = 0.017). The importance of PVL awareness for periodontists is underscored by the frequency of gingival involvement and the high prevalence of malignant transformation on masticatory mucosa, which usually can be suspected because of the onset of warning signs, such as rapid growth of verrucosity, area of erosion or ulceration, acquisition of red areas, induration, and positive response to toluidine blue staining.