Histology of the nasal swell body

Abstract

Objectives: The nasal swell body is a widened region of the septum located superior to the inferior turbinates and anterior to the middle turbinates, and of potential importance to the airflow-regulating nasal valve. Although little is known of this structure in terms of vasoreactivity and tendency to limit airflow by vascular engorgement, some consider the swell body to be physiologically analgous to the inferior turbinate. This study addressed whether the septal swell body contains abundant vascular structures and general histologic similarity to the inferior turbinate. Methods: Ten adult patients undergoing septoplasty and inferior turbinate reduction were submitted to unilateral biopsies of the nasal swell body and the adjacent inferior turbinate. Histologic sections were stained with Masson trichrome and subjected to histomorphometric analysis of photomicrographs. Results: The swell body was rich in seromucinous glands (mean, 48.6% + 7.6%; range, 31.3%-55.9%) compared to the inferior turbinate (mean, 19.2% + 4.3%; range, 13.8%-27.2%), P < 0.01. Conversely, the inferior turbinate mucosa demonstrated increased amount of vascular structures (mean 31.1% + 5.9%; range, 24.5%-40.4%) compared to the swell body (mean 11.31% + 6.3%; range 5.6%-23.2%), P < 0.01. The swell body had a respiratory epthelium similar to that of the inferior turbinate. Conclusion: The nasal septal swell body is a highly glandular structure of the anterior-superior septum, with lesser mucosal vascularity than that of the inferior turbinate. These histologic data suggest that the septal swell body has reduced potential for mucosal engorgement relative to the inferior turbinate, and a more prominent role in humidification of the inspired airstream.