Nasal polyps are soft, fleshy masses that can arise from the nasal mucosa. Histologically, there are different types of nasal polyps ranging from inflammatory to neoplastic. The most common type is the oedematous allergic nasal polyp, which is lined by thickened epithelium and contains eosinophils, plasma cells and lymphocytes in the submucosa. Chronic inflammatory polyps can develop from traumatized allergic polyps and contain submucosal fibrosis. Rarely, seromucinous polyps can occur due to glandular hyperplasia. Microscopic examination is important for classification and diagnosis of underlying conditions.
9. The rest of the nasal cavity is lined by respiratory type of epithelium (Schneiderian membrane)
10. The lining mucosa of paranasal sinuses is rather thinn when compared to that of nasal cavity
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12. It is composed of 4 cell types – ciliated columnar / cuboidal cells, interspaced goblet cells, nonciliated columnar cells with microvilli and basal cells
19. The basement membrane is thin and delicate in the whole of nasal cavity except for inferior turbinate area.
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21. Lines superior turbinate, superior portion of nasal septum, roof of nasal cavity and medial portions of middle turbinate
22. This epithelium is also pseudostratified ciliated columnar containing bipolar olfactory cells, microvillar cells and supporting sustentacular cells
23. ! Note Due to aging / infections olfactory Epithelium could be replaced by Normal nasal mucosa