OBJECTIVE: This study investigates olfactory epithelium biopsies from patients with nasal polyposis, in correlation with olfactory test results and ratings of olfactory dysfunction pre- and postoperatively.

MATERIAL & METHODS: Twenty-seven patients with nasal polyposis were included. Olfactory function was tested with the "Sniffin Sticks" test. Biopsies from the olfactory region performed at the end of endoscopic surgery and studied with immunohistochemistry. Patients used a visual analogue scale to report their olfactory dysfunction when re-examined one year postoperatively.

RESULTS: Subjects with little or no inflammation in olfactory and respiratory biopsies had short-er duration of disease and better olfactory function. Pathological changes of olfactory mucosa included replacement by respiratory metaplasia, degenerated epithelium, rupture of epithelial surface and infiltration by inflammatory cells. Postoperative olfactory test results showed improvement of olfaction in 74% of patients. Although this improvement seemed to be better in subjects with little or no inflammation, this was not significant. Preoperative and postoperative olfactory test results were positively correlated.

CONCLUSIONS: The disease process includes loss of structural organization and inflammatory infiltration of the olfactory epithelium. The inflammation severity is related to the olfactory test results; however, it cannot be the only predictive factor postoperatively.