Histopathologic features of biologic therapy nonresponders in chronic rhinosinusitis with nasal polyposis.

Histopathologic analysis of biologic nonresponders demonstrates decreased eosinophilia and thickened basement membranes. These findings, particularly low tissue eosinophils, are consistent with a non-type 2 CRSwNP that may be recalcitrant to biologic therapies. Histopathologic analysis done in conjunction with FESS may aid clinicians in understanding response to biologic therapies in patients with CRSwNP who have persistent symptom burden necessitating FESS.