Pithelioma Following Lichen Planus of the Mouth.

Oral lichen planus:

“…It could be that the type of patient likely to have lichen planus is also more likely to smoke, perhaps due to nervous tension. Others have expressed similar concerns that malignancies superimposed upon oral lichen planus may be primarily due to other factors (Warin 1960, Andreason & Pindborg 1963, Cernea 1971. In Andreason and Pindborg's report of 46 transformations, a relatively high percentage of female lichen planus patients later developed oral cancer.…”

Oral Lichen Planus and Malignant Transformation: Is a Recall of Patients Justified?

“…S everal prospective Silverman et al, 1991) and retrospective studies (Warin, 1960;Altman and Perry, 1961;Janner et al, 1967;Abramova, 1968;Andreasen, 1968;Cawson, 1968;Shklar, 1972;Fulling, 1973;Kovesi and Bánóczy, 1973;Holmstrup and Pindborg, 1979;Vas'kovskaia and Abramova, 1981;Silverman et al, 1985;Murti et al, 1986;Salem, 1989;Sigurgeirsson and Lindelof, 1991;Voute et al, 1992;Barnard et al, 1993;Brown et al, 1993;Moncarz et al, 1993;Duffey et al, 1996;Markopoulos et al, 1997;Silverman and Bahl, 1997;Lo Muzio et al, 1998;Rajentheran et al, 1999) as well as case reports (Faraci et al, 1975;Marder and Deesen, 1982;Pogrel and Weldon, 1983;Fowler et al, 1987;Katz et al, 1990;Massa et al, 1990;Harland et al, 1992;Porter et al, 1997;Camisa et al, 1998;Chainani-Wu et al, 2001) have reported oral lichen planus (OLP) as having an increased potential for malignant development. The reported transformation rates vary from 0 to 9%.…”

The Association of Lichen Planus of the Penis with Squamous Cell Carcinoma in Situ and with Verrucous Squamous Carcinoma

“…In some cases, external factors were thought to play a role in carcinogenesis. These included exposure to potentially carcinogenic therapies such as radiation or arsenicals, 7, 10–12 or other drugs, 12 the presence of alcohol or tobacco abuse, 6, 7 or trauma and irritation resulting from contact with teeth or dentures 3, 8 …”