Localization and characterization of human papillomavirus-16 in oral squamous cell carcinoma.

OBJECTIVES: The role of Human papillomavirus (HPV) in the oral squamous cell carcinoma (OSCC) has not been completely elucidated. The purpose of the present study was to investigate the prevalence and localization of HPV-16 virus in OSCC and to correlate HPV-16 positivity and p16INK4A expression with the clinical and pathological features of OSCC. METHODS: The archives of Oral Pathology at the University of Florida, College of Dentistry were accessed for demographic, clinical, histopathological data, and slides of 114 OSCC patients. HPV-16 positivity of OSCC was evaluated by p16INK4A immunohistochemistry (IHC) and HPV-16 E6/E7mRNA by in situ hybridization (ISH). RESULTS: Out of 114 consecutive pathological slides of OSCC, 16 samples (14%) showed positivity for p16INK4A by IHC and 14 samples (12%) were positive for HPV-16 E6/E7mRNA ISH and the Positivity showed a significant correlation with the patients' age, alcohol consumption, and the degree of OSSC differentiation. The hard palate showed the highest positivity of p16INK4A IHC and HPV-16 mRNA ISH (38%, 36% respectively). CONCLUSION: HPV-16 is a significant factor in oral carcinogenesis. We recommend using p16INK4A as a surrogate marker for HPV detection in OSCC, which can be complemented by RNA ISH for the identification of HPV subtypes.

Squamous Odontogenic Tumor: Review of the Literature and Report of a New Case.

PURPOSE: Squamous odontogenic tumor (SOT) is a rare, benign, locally infiltrative odontogenic tumor of the gnathic bones. It is composed of islands of bland, well-differentiated squamous epithelium of varying shape and size. Because of histologic overlap, SOT has often been overdiagnosed as ameloblastoma and squamous cell carcinoma. It thus becomes important to understand the clinical, radiologic, histopathologic, and treatment characteristics of this tumor. MATERIALS AND METHODS: Using the PubMed and Google Scholar databases, we searched for reported cases of SOT published in the English-language literature. We were able to retrieve 49 acceptable cases and perform a comprehensive literature review of the intraosseous SOTs, with emphasis on their clinical, radiographic, and pathologic characteristics, as well as treatment strategies. In addition, we present an additional case of SOT affecting the posterior mandible in a 44-year-old female patient. RESULTS: The tumor in the posterior mandible in our patient was accompanied by acute pain and treated by enucleation. Histopathologic evaluation showed variably sized islands of benign squamous epithelium scattered in a fibrous stroma, consistent with the diagnosis of an SOT. Uneventful healing was noted at the 1-month postoperative appointment. However, the patient was lost to long-term follow-up. Our literature review showed that the average age at the time of diagnosis of SOT is 34.2 years. Men and women are equally affected, and the tumor does not show a predilection for either jaw bone. The most common locations are the anterior maxilla and posterior mandible. Most SOTs are treated conservatively by enucleation or curettage, whereas aggressive or recurrent tumors require radical resection. CONCLUSIONS: Careful evaluation of the excised specimen, with immunohistochemical investigations, may prove rewarding in differentiating an SOT from other odontogenic neoplasms and thus minimize the patient's chances of undergoing an unnecessary aggressive intervention.