ABSTRACT
BACKGROUND AND OBJECTIVES: Inverted papilloma is a rare benign tumor of nasal epithelium associated with high recurrence rate and malignant potential. Its etiology is still uncertain, and the mechanism of proliferation has not yet been fully described. Among the various approaches for evaluating the proliferation activity, proliferating cell nuclear antigen (PCNA) has been introduced as another marker of cellular proliferation. The purpose of this study was to detect the quantify and compare cell proliferation in the human inverted papilloma, maxillary carcinoma, nasal polyp and hypertrophic turbinate mucosa, and to analyze the relationship between PCNA expression and clinicopathologic findings in human inverted papilloma. MATERIALS AND METHODS: The samples were obtained after surgical removal from 29 patients with inverted papilloma, 5 patients with maxillary squamous cell carcinoma, 15 patients with nasal polyp, and 10 patients with hypertrophic turbinate. The cell proliferation was assessed by immunohistochemical identification of the PCNA. RESULTS: The cell proliferation was significantly higher in the inverted papilloma and maxillary carcinoma than in the nasal polyp and hypertrophic turbinate. The cell proliferation in the inverted papilloma was greater when it was associated with dysplasia. CONCLUSION: The increased epithelial cell proliferation seems to be involved in the development of the inverted papilloma, and the high PCNA expression in the inverted papilloma may serve as a useful indicator to predict the malignant transformation.