Structured Histopathologic Findings in Chronic Rhinosinusitis Patients With Intranasal Substance Use.

OBJECTIVES: To characterize structured sinonasal histopathology findings among patients with chronic rhinosinusitis (CRS) and documented intranasal substance use undergoing endoscopic sinus surgery. METHODS: Adult patients with medically recalcitrant CRS who underwent endoscopic sinus surgery between January 2021 and October 2024 were reviewed. Patients with documented intranasal substance use were compared with CRS patients without documented substance use. Demographic, clinical, and structured histopathology variables were analyzed using chi-square, Fisher exact, and Student's t-tests, as appropriate. RESULTS: Twenty-one CRS patients with documented intranasal substance use were identified. Reported substances included cannabis in 10 patients (47.6%), cocaine in 6 patients (28.6%), heroin in 2 patients (9.5%), and polysubstance use involving more than 3 substances in 3 patients (14.3%). Compared with non-users, substance users were more frequently male (76.2% vs. 46.4%, p = 0.008) and differed by CRS subtype distribution (p < 0.001). No significant differences were observed by age or race. Substance users had higher rates of neutrophil infiltrate (33.4% vs. 10.7%, p = 0.001), basement membrane thickening (100% vs. 31.0%, p < 0.001), subepithelial edema (90.4% vs. 25.8%, p < 0.001), squamous metaplasia (42.9% vs. 20.8%, p = 0.016), and fibrosis (38.0% vs. 20.8%, p = 0.013). CONCLUSION: CRS patients with documented intranasal substance use demonstrated greater neutrophilic inflammation and histologic features of epithelial injury and remodeling compared with non-users. These findings support careful substance-use assessment, cessation counseling, and postoperative surveillance in this population. Larger studies are needed to determine whether these histopathologic differences influence treatment response and surgical outcomes.