Nasal Inverted Papilloma Associated With Squamous Cell Carcinoma: A Report of Two Cases

ABSTRACT

Nasal inverted papilloma (IP) is a benign neoplasm that may be associated with squamous cell carcinoma (SCC). Several studies have suggested that human papilloma virus 16/18 (HPV 16/18) and p53 are closely related to the pathogenesis of IP with transformation to squamous cell carcinoma (IP-SCC). This study was conducted to investigate the role of HPV 16/18 and p53 in the pathogenesis of IP-SCC using immunohistochemistry. We studied two cases of IP-SCC and 10 cases of IP. None of the IP cases presented positivity for HPV 16/18 or p53 protein. Two cases of IP-SCC showed negative reactions for HPV 16/18. The SCC portion of the IP-SCC showed strong positivity for p53, while the IP portion of the IP-SCC was negative for p53. MIB-1 labeling index (LI) was estimated in the IP cases and the IP-SCC as well. In terms of MIB-1 LI, there was no statistical significance between IP and IP-SCC, and between the IP portion and the SCC portion in the cases of IP-SCC. In conclusion, we believe that alteration of the p53 protein is related to IP with malignant transformation, but further studies are required to investigate the correlation of HPV 16/18 and p53 in the pathogenesis of IP with malignant transformation, and the significance of the MIB-1 LI and p53 as biomarkers in IP.