Oral Lichen Sclerosus: A Rare Case Report and Review of the Literature.

Lichen sclerosus (LS) is a chronic inflammatory mucocutaneous disease that often affects the anogenital area and causes significant discomfort and morbidity. Oral mucosal lesions in LS are extremely rare and might be associated with genital and/or skin manifestations. As a unique manifestation of LS, oral lesions are even more rare, with only 20 cases reported in English-language literature. In reviewing that literature in this paper, we present the case of a 44-year-old white man who sought dental assistance with a complaint of a white spot on his upper lip. Extraoral clinical examination revealed a slight white macule on the left upper lip vermilion next to the labial commissure. Intraoral examination revealed that the macule was approximately 3.5 × 2.0 cm, extended to the upper left labial mucosa, and presented an ivory-white color. Following an incisional biopsy and microscopy, the lesion was shown to be covered by a stratified squamous epithelium showing hyperkeratosis and atrophy. The superficial lamina propria revealed a well-marked band of subepithelial hyalinization and, below it, a band-like mononuclear inflammatory infiltrate. Sections stained by Verhoeff's technique revealed a scantiness of elastic fibers in the superficial lamina propria. The diagnosis of LS was then established. The patient was referred for dermatologic evaluation, which identified no skin or genital lesions, and no treatment was employed. After 6 years, no significant changes in clinical features were observed. Altogether, this rare case makes an important contribution to knowledge on this uncommon condition.