“…The disease is featured by single or multiple fibrous, well-defined lesions like nodules and papules which frequently coalesce, with a size range from 0.1 cm to 1 cm in diameter. These lesions are usually painless and mainly found on the mucosa epithelia of the lower lip, upper lip, tongue and hard palate (Buchner et al, 1975;Mealey et al, 1993;Morrow et al, 1993;Pilgard, 1984;Sawyer et al, 1983). The main histological characteristics include epidermal acanthosis and parakeratosis, thickening and elongation of the rete ridges, and pronounced koilocytosis with characteristic mitosoid figures (van Wyk et al, 1977a).…”