Koilocytes in oral pathologies

Abstract

Introduction: Oral HPV infections affect 1 to 50% of the general population. Naturally, about 90% of HPV is eliminated by the immune system, but the ones that persist may result in serious diseases. Human papillomavirus is the main cause of cancer at various body sites, such as cervix, uterus, oropharynx, head and neck. The prevalence of oral HPV infections in India ranges from 15 to 16%. About 80% of HPV infections are present with koilocytosis as an important morphological marker. Aim: This review focuses on the importance of koilocytes and its early detection to alert malignant risk for facilitating human papillomavirus (HPV)-targeted therapeutic strategies. Results: Research in the past has primarily focused on cervical cancer, as >99% of them harbor HPV. It has been observed that the incidence of HPV-associated cancers may be minimized by effective preventive and targeted therapeutic modalities. Although oral HPV infections have been minimally researched lesions such as verruca vulgaris, squamous papilloma, focal epithelial hyperplasia and condyloma acuminatum are significantly prevalent in India. The characteristic cell observed in all these HPV-associated lesions is koilocytes as demonstrated using immunohistochemistry (IHC) with p16 antibody. Although advanced techniques, such as polymerase chain reaction (PCR), deoxyribonucleic acid (DNA) breakage detection fluorescence in situ hybridization (DBD-FISH), and comet assay may confirm their presence, they are cumbersome and not economical. Conclusion: Detection of malignancy-prone oral HPV infections by the demonstration of koilocytes showing positivity to p16 IHC stain has shown promising avenues in the field of research for the prediction of diagnosis and prognosis of oral squamous cell carcinomas (OSCC). Clinical significance: Koilocytic cells are pathognomonic of HPV infection. Identification of koilocytes in histopathologic sections alerts the pathologist to suspect any underlying HPV infection and directs the surgeon for appropriate treatment. Human papillomavirus infection affects the function or host gene expression that is marked by cellular changes, and unmasking of such changes has an important role in the identification and follow-up of such patients.