Histopathological characteristics of surgical tissue from primary vs recurrent chronic rhinosinusitis with nasal polyposis patients

Abstract

Objective The histopathological characteristics of primary vs recurrent nasal polyps in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) have not been studied comprehensively. Identification of these features may be helpful for prognostication, postoperative management, and consideration of novel eosinophil‐targeting biologic therapy. This study investigates the histopathological differences in primary vs recurrent CRSwNP tissue. Methods Patients undergoing endoscopic sinus surgery for CRSwNP were included if all 13 histopathological and mucin characteristics on a standardized report were available. Histopathology parameters were compared in surgical tissue and mucin from primary vs recurrent CRSwNP. Results Complete structured histopathology reports were available for 96 patients (39 primary polyps and 57 recurrent polyps). Compared to primary polyp tissue, recurrent CRSwNP mucin was significantly more likely to feature eosinophil aggregates (57.9% vs 35.9%; P = .047). Tissue eosinophilia (using a threshold >10 per high power field [HPF]) was not significantly different in primary and recurrent CRSwNP tissue. Other histopathologic parameters and clinical characteristics were similar. Conclusion Eosinophil aggregates on histopathology are significantly more likely to be present in recurrent CRSwNP. In the limited series, tissue eosinophilia (>10 per HPF) was not significantly different in primary and recurrent CRSwNP. Therefore, in addition to the study of tissue eosinophilia levels, Rhinologic surgeons should also direct attention to CRSwNP mucin. Mucin eosinophilic aggregates are an independent marker of severe inflammation that is associated more likely with recurrent vs primary polyposis. Further study of this marker may help determine its role of choice of postoperative medical therapies, including anti‐eosinophilic biologics. Level of Evidence 4

Comparative Histopathological Changes Between Primary Versus recurrent Rhinosinusitis With Nasal Polyposis

“…The current research aimed to evaluate cellular, epithelial and stromal inflammatory indicators in cases with primary and recurrent chronic nasal polyposis. Despite a variety of inflammatory markers being used in this study after FESS, mucosal eosinophilia and basal membrane thickness [BMT] showed a statistically significant difference between primary and recurrent chronic polyposis in rhinosinusitis cases, however, eosinophilia showed weak significant values [P = 0.044] and eosinophil aggregates [P = 0.049] which was similar to Donnell et al [12] who found that increasing eosinophils have more eosinophil aggregates [P < 0.001]. The presence of eosinophilia in primary and recurrent CRSwNP were studied extensively more than eosinophilic aggregates [7,[13][14] .…”

“…Eosinophils are the most prevalent inflammatory cells in nasal polyp tissues, except in cases of cystic fibrosis. Steroids diminish eosinophilic infiltration of the upper airway by decreasing eosinophil viability [7][8][9][10][11][12][13][14][15] . The increase in eosinophils in chronic recurrent polyposis can be explained because These cells release mediators such as eosinophil-derived neuro-toxin and eosinophil cationic protein and can also synthesize a number of regulatory molecules such as transforming growth factor β and interleukin-4, which can directly or indirectly contribute to the further recruitment and activation of eosinophils capable of causing cellular injury and tissue damage [16] .…”

Latest advances in chronic rhinosinusitis with nasal polyps endotyping and biomarkers, and their significance for daily practice

“…Following studies used structured HP reporting looking to distinguish histological markers in order to stratify subtypes and discern the puzzling pathophysiological mechanisms in CRS [31][32][33]. The association of HP findings with clinical features of CRS and CRS categories was investigated recently using 99 patients and 13 variables [31].…”

“…The HP aspect of the polyp specimens was typified by Donell et al [33] in primary vs. recurrent CRSwNP patients undergoing ESS. The authors did not find any disparity between primary and recurrent CRSwNP for eosinophilic infiltrated tissue, but in recurrent CRSwNP cases mucin was quite often inclined to presents eosinophil aggregates compared to primary CRSwNP.…”

“…One is related to the number of eosinophils that should define tissue eosinophilia. Various reports have suggested different threshold values for tissue eosinophilia, ranging from >5 eosinophils/HPF to >120 eosinophils/HPF [39][40][41], most recommending >10 eosinophils/HPF [33,42]. The same is also suggested as a reference value in the new European Position Paper on Rhinosinusitis (EPOS) Guide [11].…”