Histopathologic features of chronic rhinosinusitis with nasal polyps in patients from high-altitude Xizang region

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a heterogeneous inflammatory disease with varying patterns across regions.

This study aims to investigate the clinical and histopathological features of CRSwNP in Xizang, a high-altitude region in China.

We retrospectively analyzed the histopathological features of CRSwNP patients from Shanghai and Xizang who underwent functional endoscopic sinus surgery (FESS) between 2017 and 2024. Polyp tissue samples were assessed, and statistical analyses compared features between the two regions in CRSwNP, eosinophilic CRSwNP (eCRSwNP), and noneosinophilic CRSwNP (neCRSwNP) patients.

Twenty-eight patients from Xizang and 35 from Shanghai were analyzed. All Shanghai patients were Han Chinese, and all Xizang patients were Tibetan. Compared to Shanghai, Tibetan patients had significantly lower rates of smoking and asthma. Overall inflammation levels in Xizang were lower, while eosinophil counts were lower in eCRSwNP patients. Neutrophil infiltration, mucosal ulceration, and squamous metaplasia were higher in Xizang patients, while neCRSwNP patients exhibited more neutrophil infiltration and less subepithelial edema.

The study revealed that Tibetan patients with CRSwNP have lower eosinophilic inflammation but higher neutrophil infiltration and squamous metaplasia compared to Shanghai patients, indicating the impact of high-altitude environments on inflammatory patterns.