Neutrophil infiltrates and eosinophil aggregates in chronic rhinosinusitis with nasal polyps and EGPA.

Structured histopathology is increasingly identifying the different histotypes of CRSwNP. This analysis can be used to better understand CRSwNP endotypes and develop targeted therapies. The response to therapy and therefore control of CRSwNP relapses definitely depends on our ability to act on the underlying inflammatory pattern. Key points • Systematic analysis of how neutrophil infiltrates and eosinophilic aggregates are distributed in the different phenotypes of CRSwNP and EGPA. • Neutrophil infiltrates and eosinophil aggregates are strong risk factors for nasal polyps' refractoriness. • NERD and ECRSwNP are the sub-cohorts of CRSwNP with the highest rate of tissue eosinophil aggregates. • Neutrophil infiltrates are significantly higher in EGPA.