Cytokeratin expression in reactive cylindrical ciliated epithelium of the sinonasal tract in chronic inflammation

Abstract

Introduction. Currently, there are limited papers on changes in the pseudostratified ciliated columnar epithelium of the sinonasal tract in chronic inflammatory processes, particularly in basal cell hyperplasia. The latter is similar to dysplasia of varying severity of the stratified squamous nonkeratinized epithelium. Studying of changes in the pseudostratified ciliated columnar epithelium can clarify the histogenesis of various epithelial tumors of the sinonasal tract, including sinonasal papillomas. The research is aimed at studying the cytokeratin profile of reactive cylindrical ciliated epithelium in a chronic nonspecific inflammatory process. Materials and methods. We analyzed surgical materials obtained from 567 patients diagnosed with chronic rhinosinusitis with nasal polyps. We performed an immunohistochemical study in 20 cases using the panel of antibodies to Ki-67, Stathmin, Cytokeratin 7, Cytokeratin 10/13, Cytokeratin 14, Cytokeratin 17, Cytokeratin 18, and Cytokeratin 19. Results. Using hematoxylin and eosin staining, we detected basal cell hyperplasia of different severity in 74% (419 cases). In 13% (73 cases), basal cell hyperplasia was combined with foci of squamous metaplasia. Based on the results, we identified 4 types of morphological changes in the epithelial layer with a specific cytokeratin profile: mild basal cell hyperplasia, moderate basal cell hyperplasia, severe basal cell hyperplasia, and areas of squamous metaplasia. Conclusion. Simultaneous expression of cytokeratins in the areas with severe hyperplasia of basal cells, specific for both simple and compound epithelia, allows us to consider this area to have the highest potential for the development of various epithelial tumors of the sinonasal tract, including various types of sinonasal papillomas. Keywords: basal cell hyperplasia, sinonasal papilloma, pseudostratified columnar ciliated epithelium