Lichen Sclerosus of the Upper Lip: Report of a Case, Utilizing Shikata's Modified Orcein Stain, and Review of the Literature.

Objectives: Lichen sclerosus is a rare chronic inflammatory disorder, affecting mainly the skin and the anogenital mucosa, while oral lesions can be the primary or the only manifestation of the disease. A rare case of oral lichen sclerosus, assessed histopathologically and histochemically, is presented, along with a thorough review of the English language literature.

Material and Methods: A 32-year-old female presented an asymptomatic white patch affecting the skin and the mucosa of the upper lip, without other mucocutaneous involvement. A partial biopsy of the lesion was performed, along with the histochemical Shikata's modified orcein stain for elastin fibres detection. A literature review was also performed, discussing the epidemiological data, clinical presentation, and treatment modalities of all published cases with oral involvement.

Results: The histopathological evaluation revealed the presence of acellular zone underneath the basal layer of the epithelium, accompanied by deep band-like chronic inflammation. Shikata's modified orcein stain exhibited scarcity or loss of elastin fibres in the acellular subepithelial area. The diagnosis of lichen sclerosus was made. Topical application of corticosteroids was prescribed and resolution of the lesion was observed. Literature review revealed that oral lichen sclerosus is predominantly presented in females, as asymptomatic lesions of the lips and buccal mucosa; few cases have extraoral manifestations and topical corticosteroids are the main treatment intervention.

Conclusions: Despite its rarity, lichen sclerosus should be considered in the clinical and histopathological differential diagnosis of white patches of the oral mucosa. For rendering proper diagnosis, the histochemical Shikata's modified orcein stain is a useful assessment tool.