Keratinizing odontogenic cyst with verrucous pattern featuring negative human papillomavirus status by polymerase chain reaction

Verrucous odontogenic cysts (OCs) are extremely rare. Here, we report the clinicopathologic features of this unusual entity and investigate the role of human papillomavirus (HPV) by p16INK4A immunohistochemistry and HPV-DNA polymerase chain reaction (PCR). A 32-year-old male presented with a 8.3 × 4.0 cm, multilocular radiolucency of the left ascending ramus of the mandible. Microscopically, the cystic cavity was lined by hyperplastic stratified squamous epithelium demonstrating marked verrucous morphology with multiple sharp or blunt projections. Mild dysplastic features were also identified. A final diagnosis of keratinizing OC with verrucous hyperplasia and epithelial dysplasia was rendered. Immunohistochemically, the verrucous OC showed foci of moderate-to-intense and diffuse, nuclear, and cytoplasmic p16INK4A positivity as well as weak or absent p53 immunopositivity in the p16INK4A labeled areas. The Ki-67 expression was increased. Interestingly, HPV-DNA PCR failed to reveal transcriptionally active HPV genotypes. Complete surgical excision was performed, with no recurrences seen during a 66-month follow-up.