Pathomorphology of chronic polypous purulent rhinosinusitis in cystic fibrosis in children

Cystic fibrosis (CF) is a systemic autosomal recessive hereditary condition that is caused by a mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Chronic rhinosinusitis, which is a source of infection of the underlying respiratory tract, is one of the main CF manifestations. Objective. To study the pathomorphological characteristics of the mucous membrane of the paranasal sinuses (PNSs) with polypoid changes in CF and compare them with nasal polyps in chronic rhinosinusitis with nasal polyps (CRSwNP) in children and adolescents without CF. Material and methods. The study included histological specimens obtained from 97 patients with a confirmed diagnosis of cystic fibrosis who underwent endoscopic endonasal sinus surgery. The control group consisted of 29 patients with CRSwNP without CF. Results. It has been established that intraepithelial microabscesses, intraepithelial microcysts and gland cysts were significantly more often detected in patients with CF compared to the subjects with CRSwNP. Patients with CF are characterized by lower eosinophil-neutrophil ratio (ENR) rates compared to subjects with CRSwNP. There has been no relationship between genotype and pathomorphological characteristics of the mucous membrane of the PNSs in CF. Conclusion. The presence of intraepithelial microabscesses, intraepithelial microcysts and gland cysts can be considered as a pathomorphological marker of CF. Identification of these histological features in combination with a low value of the ENR will allow to suspect CF in patients with CRSwNP. Low ENR rates in patients with CF were suggestive of intranasal glucocorticosteroids’ insufficient effectiveness in the treatment of patients with this disease.