Clinicopathological study of nasal polyps with special reference to mast cells in inflammatory polyps

Background and aim: Nasal polyposis is a relatively common condition found in 1–4% of the general population and in high percentages of some groups of patients. Nasal polyps diagnosed clinically are not always of inflammatory origin. A variety of non-neoplastic and neoplastic conditions can present as nasal polyps. The aim of this study was to determine the various histopathological types, the predominant cells involved in the pathogenesis of inflammatory polyps with special reference to mast cells and to correlate them clinicopathologically. Methods: A total of 100 cases clinically diagnosed as nasal polyp, were studied over a period of 18 months. Results: Out of 100 cases studied, 91% of them were non-neoplastic and 9% were neoplastic. Among the non-neoplastic conditions, non-allergic polyps accounted for 70% and allergic polyps accounted for 21% of cases. Among the neoplastic lesions, 6% were benign and 3% malignant. Squamous metaplasia was seen in 16.38% of cases. In stroma, mononuclear cells were predominant in 63.7% of inflammatory polyps, eosinophils in 19.11%, prominent edematous stroma in 26.39%, and vasculature > 2/high power field (hpf) in 20.39% of inflammatory polyps. 0–5 mast cells per 10 hpf were seen in 97.8% of inflammatory polyps in epithelium, whereas 11–20 mast cells in 26.4% of inflammatory polyps were seen in stroma. Conclusions: Nasal polyps diagnosed clinically are not always of inflammatory origin and therefore have to be subjected for histopathology.