비·부비동 반전성 유두종에서 인체유두종 바이러스와 p16의 발현

Background and Objectives: Clinicopathologically inverted papilloma (IP) shows dynamic range of broad spectrum from inflammatory polyp with squamous metaplasia to malignant transformed squamous cell carcinoma (SCC) . Correlation between human papilloma virus (HPV) and IP has been reported. However, the involvement timing and types of HPV in the evolution of multistep stages of IP are unknown. The aim of this study was to determine HPV types and the timing of HPV infection during IP tumorigenesis and to know relationship with HPV infection and histological grades in IP by evaluation of p16^INK4 expression as a surrogate marker of HPV infection. Patients and Methods: Of 57 formalin-fixed paraffin-embedded specimens which had been taken from 38 sinonasal IP patients, 5 specimens were classified as grade I, 23 specimens as grade II, 22 specimens as grade III and 7 specimens were grade IV. The presence of HPV DNA was evaluated by laser captured microdissection in the representative lesion of each grade. Results: HPV DNA was expressed in 7 specimens (12.3%). 5 specimens were high-risk HPV types and 2 specimens were unspecified types. All of the HPV DNA positive lesions were grade I and II. Overall p16 protein overexpression was observed in 45.6% of sinonasal IP and 60.0% in grade I, 47.8% in grade II, 45.5% in grade III and 28.6% in grade IV There was statistical significance between of p16 expression and HPV DNA regardless of grades (p=0.039). Conclusion: HPV infection, mainly high-risk types, occurs in the benign IP as an early event during multistep tumorigenesis of IP. (J Clinical Otolaryngol 2006^;17: 203–211)