Abstract: To detect the expressions of epidermal growth factor receptor (EGFR) and Ki67 in inverted papilloma of nasal cavities and paranasal sinuses and investigate their clinicopathological significances in occurrence and aggravation of this disease. Methods： Immunohistochemical technique (SP staining method) was used to detect the expressions of EGFR and Ki67 in 17 cases of inverted papilloma(IP) arising from nasal cavity and paranasal sinuses and 7 cases of squamous cell carcinoma aggravating from inverted papilloma (IP+SCC) and 12 cases of nasal polyp tissues(NP). Results： The labelling index (LI) of Ki67 positive cells was significantly higher in IP+SCC than in IP(F=12.87, P=0.001?6) and NP(F=17.50, P=0.000?6), and a significant difference was also found between IP and NP(F=6.45, P=0.017?2). EGFR expression rate was 11.76%(2/17), 57.14%(4/7) and 8.33%(1/12) in IP, IP+SCC and NP respectively, and significant differences were found between IP+SCC and IP(χ2=6.708, P=0.035), between IP+SCC and NP(χ2=7.937, P=0.018?9), respectively, but no significant difference was found between NP and IP(χ2=0.000?2, P=0.989?6). Conclusions： Immunohistochemical features of Ki67 indicate that increased epithelial cell proliferation seems to be involved in the development and aggravation of nasal cavity and sinuses inverted papilloma. EGFR may play an important role in arising squamous cell carcinoma from inverted papilloma of nasal cavity and paranasal sinuses, but has no relation with the occurrence of nasal inverted papilloma.

Key words: Inverted papilloma, Epidermal growth factor receptor, Antigen, Ki67, Nasal cavity, Paranasal sinuses, Immunohischemistry