Abstract: Objective: To explore the function of MMP-9 and PCNA in the occurrence, recurrence and malignancy of the sinonasal inverted papilloma (SNIP). Methods: Forty specimens with SNIP and ten specimens with squamous cell carcinoma (SCC) were selected for this study. All the specimens were divided into four groups: the SNIP group, the recurrent SNIP group, the SNIP with carcinoma group, and the invasive squamous cell carcinoma (SCC) group. The expression of MMP-9 and PCNA was determined by using an immunohistochemistry method. The results were analyzed by a quantitative immunohistochemical analysis. Results: Expression of increased in the SNIP group, the recurrent SNIP group, the SNIP with carcinoma group, and the SCC group. According to the rank test, the expression of MMP-9 was significantly different between the SNIP group and other groups. But between recurrent SNIP and SNIP with carcinoma, recurrent SNIP and SCC, SNIP with carcinoma and SCC, there were no prominent differences. The expression of PCNA was not significantly different between any two groups. Conclusion: The expression of MMP-9 and PCNA is involved in the mechanism of the occurrence of SNIP and plays an important role in the recurrence and malignancy of SNIP. The over expression of MMP-9 and PCNA may be associated with early events in the recurrence tendency and carcinogenesis/transformation to SNIP.

Key words: Nose neoplasms, Nasal cavity, Paranasal sinuses, Gelatinase B, Proliferating cell nuclear antigen, Immunohistochemistry