Histopathological Evidence of Persistent Remodeling in Recurrent Acute Rhinosinusitis

Area of Science:

• Otolaryngology
• Rhinology
• Pathology

Background:

• Recurrent acute rhinosinusitis (RARS) is often considered episodic with full mucosal recovery between attacks.
• However, limited histopathological data exists to support this assumption.
• Investigating persistent mucosal changes in RARS is crucial for understanding disease mechanisms.

Purpose of the Study:

• To evaluate persistent mucosal inflammatory and remodeling changes in patients with RARS during asymptomatic intervals.
• To compare these changes with those in nonsinusitis surgical controls.

Main Methods:

• Prospective observational study analyzing sinonasal mucosal specimens from adult RARS patients and controls.
• Exclusion criteria included chronic rhinosinusitis, active infection, or recent systemic corticosteroid use.
• Histopathological analysis focused on neovascularization, submucosal fibrosis, inflammatory infiltration, and basement membrane thickness.

Main Results:

• RARS specimens showed significantly higher neovascularization and submucosal fibrosis compared to controls.
• While inflammatory infiltration was numerically higher in RARS, it did not reach statistical significance.
• Severe inflammation was exclusively observed in RARS specimens; basement membrane thickness did not differ between groups.

Conclusions:

• Recurrent acute rhinosinusitis (RARS) is associated with persistent mucosal neovascularization and fibrosis, even during clinical quiescence.
• These findings indicate that RARS may involve continuous interepisode tissue remodeling.
• The study challenges the traditional view of RARS as purely episodic.