Pediatric chronic rhinosinusitis histopathology: differences and similarities with the adult form.

Objective: To compare the histopathology and immunohistochemistry of pediatric and adult chronic rhinosinusitis (CRS).

Study Design: Cross-sectional study.

Setting: University-affiliated hospital.

Patients And Methods: Inflamed sinus-mucosal samples of 16 children (mean age, 11.6 ± 2.9 years) with refractory CRS who underwent endoscopic sinus surgery were studied. Twenty-nine diagnosis-matched adults served as controls. Study analysis covered sinus computed tomography (CT) scores, general pathologic features, eosinophil and T-lymphocyte population, and thickness and integrity of the epithelium.

Results: Children had a lower CT score than adults did (P = .005). The inflammatory response of the children, which differed greatly from that of adults, was dominated by cellular infiltration of the lamina propria with chronic inflammatory cells and fibrosis (8/16 had extensive fibrosis); eosinophils were scanty. Adult CRS was characterized by polypoid mucosa and eosinophilia (type A) or glandular hyperplasia (type B). Extensive fibrosis was shown in adult type-B patients (7/13). Assessment of eosinophils in the lamina propria showed marginal statistical significance between children and adults (P = .065). This difference was accentuated when pediatric and adult type A were compared (14.6 ± 25.3 vs 121.5 ± 174.2 cell/mm(2); P = .043). Complete epithelial shedding was less significant in children (9.4% ± 8.2% vs 25.4% ± 15.1%; P < .001). The number of lamina propria and epithelial T lymphocytes was similar.

Conclusions: The marked differences in the inflammatory response of children and adults with CRS may attest to different pathophysiologic pathways. The significantly reduced epithelial shedding in children is probably associated with diminished tissue eosinophilia. Extensive fibrosis was found in half of adult type-B patients; similar findings were found in children.