Fig. 1

Histological assessment of mucosa in Eos CRSwNP (a) and Non-Eos CRSwNP (b) (H&E, × 200 magnification). a A representative sample from tissue of a patient with Eos CRSwNP patient demonstrating infiltration by a large number of eosinophils and a severely edematous basement membrane. b A representative sample from tissue of a patient with Non-Eos CRSwNP patient demonstrating infiltration by large numbers of neutrophils. Eos CRSwNP = eosinophilic chronic rhinosinusitis with nasal polyps. Non-Eos CRSwNP = non eosinophilic chronic rhinosinusitis with nasal polyps