LAUSR

Background Human papillomavirus (HPV)-associated oral intraepithelial neoplasia is a subset of oral dysplastic lesions with the presence of transcriptionally active high-risk oncogenic HPV subtypes 16 and 18. There is limited evidence in the literature regarding the potential rate of transformation of this entity to oral squamous cell carcinoma. Case Report A 51-year-old male patient with a heavy smoking (35 pack-year) and alcohol consumption (6 standard drinks a day) history presented with widespread oral leukoplakia. Initial biopsies demonstrated the following: Site Histopathology findings 1. Floor of mouth Keratosis with moderate to focally severe epithelial dysplasia 2. Left lower lip Actinic keratosis with mild to moderate epithelial atypia Subsequent mapping biopsies (sites 3, 4) and wide local excision (site 5) demonstrated: 3. Left ventral tongue HPV-associated intraepithelial neoplasia 4. Lower lip carcinoma in situ 5. Right anterior ventral tongue/floor of mouth HPV-associated intraepithelial neoplasia, with excision margins free of dysplasia Investigations For sites 3 and 5, immunoperoxidase stains demonstrated diffuse, positive p16 staining of dysplastic epithelium and HPV-16 in situ hybridization showed positive nuclear staining. Both sites demonstrated hyperkeratosis, basal cell hyperplasia, increased numbers of mitoses (including suprabasal), and interspersed apoptotic cells. Follow-Up Wide local excision of the anterior ventral tongue and floor of mouth demonstrated HPV-associated intraepithelial neoplasia with involved margins (p16 and HPV-16-ISH positive). The lower lip vermilionectomy showed carcinoma in situ with clear margins. There is ongoing 3 monthly mucosal surveillance. Discussion Further studies are required to evaluate the behavior and prognosis of this subset of HPV-related oral dysplastic lesions.