Proliferative verrucous leukoplakia; a critical appraisal of the diagnostic criteria

Since its introduction in the literature in 1985, the term proliferative verrucous leukoplakia (PVL) has been the subject of an ongoing discussion with regard to its definition. Widespread or multifocal occurrence of oral leukoplakia is not just synonymous to PVL. In the present treatise the proposal is made to require the involvement of more than two oral oral subsites, a total added seizeof the leukoplakic areas of at least 3 centimeters, and a well documented period of at least five years of disease evolution being characterized by spreading and the occurrence of one or more recurrences in a previously treated area. Key words:Oral premalignant lesions, leukoplakia, verrucous leukoplakia.


Introduction
The term proliferative verrucous leukoplakia (PVL) has been defined by Hansen et al. (1) as a disease of unknown origin, that clinically often begins as a single white lesion and along time tends to become multifocal, growing slowly and progressively. It should be acknowledged that some lesions may initially be pinkish or even red rather than white. Hansen et al. (1) description of �VL includes the predilection for elderly women, a strong tendency to recur after treatment and, in many cases, inevitably, the development of squamous cell carcinoma. Tobacco habits were quite common in Hansen et al. (1) series. All sites in the oral cavity can be affected, not showing any preference for specific oral subsites. Since Hansen et al's publication many cases diagnosed as PVL have been published, questioning the etiology, diagnostic criteria and appropriate treatment. In general, the diagnostic criteria that have been used in the various studies are diverse and many cases actually seem to represent widespread, multifocal leukoplakia. Cerero Lapiedra et al. (2) proposed diagnostic criteria of PVL using a set of major and minor criteria (Table  e412 1). Some of these criteria are well accepted, but others seem to be somewhat debatable. In this treatise both the major and minor diagnostic criteria will be commented upon.

Major criteria (MC)
Minor criteria (mc) A A leukoplakia lesion with more than two different oral sites, which is most frequently found in the gingiva, alveolar processes and palate.
a An oral leukoplakia lesion that occupies at least 3 cm when adding all the affected areas.
B The existence of a verrucous area. b That the patient be female.

Critical appraisal of the diagnostic criteria
In order to make the diagnosis of PVL, Cerero-Lapiedra et al. (2) proposed that one of the two following combinations of criteria mentioned in

Conclusion and recommendation
The importance of the diagnosis of PVL lies in the awareness of both the clinician and pathologist that apparently innocent looking oral verrucous lesions, irrespective of their colour and irrespective of the presence of dysplasia may in time progress into verrucous carcinoma or squamous cell carcinoma.
In view of our comments on the major and minor diagnostic criteria proposed by Cerero-Lapiedra et al.
(2) we suggest to simplify the diagnostic criteria of PVL by omitting the distinction between major and minor criteria as is shown in table 2.
1. Leukoplakia showing the presence of verrucous or wartlike areas, involving more than two oral subsites. The following oral subsites are recognized: dorsum of the tongue (unilateral or bilateral), border of the tongue, cheek mucosa, alveolar mucosa or gingiva upper jaw, alveolar mucosa or gingiva lower jaw. hard and soft palate, floor of the mouth, upper lip and lower lip 2. When adding all involved sites the minimum seize should be at least three centimeters 3. A well documented period of disease evolution of at least five years, being characterized by spreading and enlarging and the occurrence of one or more recurrences in a previously treated area 4. The availability of at least one biopsy in order to rule out the presence of a verrucous carcinoma or squamous cell carcinoma Table 2. Modified diagnostic criteria for �VL; all four criteria should be met.