Alessandro De Cassai, Claudio Bonanno, Ludovica Sandei, Francesco Finozzi, Michele Carron, and Alberto Marchet. Korean J Pain 2019;32:286-91. https://doi.org/10.3344/kjp.2019.32.4.286

Different inflammatory endotypes reflect the heterogeneity of chronic rhinosinusitis with nasal polyps’ (CRSwNPs) clinical presentation. This retrospective study aimed to analyze the distribution of polyps in nasal cavities and paranasal sinuses to establish a possible association between CRSwNP endotypes, prognosis, and polyps’ extension. This study included 449 adult patients who underwent endoscopic sinus surgery for CRSwNPs between 2009 and 2022. Patients were categorized based on the number of paranasal sinuses involved by polyps. Statistical analyses, including Cox regression, were performed to identify associations between demographic, clinical, and histopathological factors and disease recurrence. CRSwNP patients were stratified into four groups based on the extent of polyp involvement. Asthma and acetylsalicylic acid (ASA) sensitivity were associated with more sinuses involved (p-values = 0.0003 and 0.0037, respectively). Blood eosinophil counts increased with the number of sinuses affected (p-value < 0.0001). The distribution of eosinophilic and non-eosinophilic histotypes varied significantly among these groups (p-value < 0.0001). The risk of CRSwNP recurrence was higher in patients with asthma, higher basophil percentages, and eosinophilic histotype (p-value 0.0104, 0.0001, 0.0118, and 0.0104, respectively). This study suggests a positive association between the number of paranasal sinuses involved by polyps and the severity of CRSwNPs, particularly in patients with eosinophilic histotype, asthma, and ASA sensitivity.