Olfactory Mucosal Findings of Patients with Persistent Anosmia Following Endoscopic Sinus Surgery

Park, Hyo Jin; Oh, Joon Hwan; Park, Ji Hoon; Ju, Eun Jeong; Lee, Heung Man; Lee, Sang Hag

Abstract

BACKGROUND AND OBJECTIVES: The olfactory mucosa in patients with persistent anosmia after endoscopic sinus surgery were immunohistochemically examined by using antimicrotubule associated protein 5 (MAP 5) and further compared with normosmic patients after surgery.
PATIENTS AND METHODS
Sixty-three biopsy specimens were obtained from the olfactory region of 15 patients with persistent anosmia and 6 patients with normosmia following sinus surgery.
RESULTS
Immuno-histochemical examination of all specimens with microtubule-associated protein 5 (MAP5) antisera demonstrated olfactory epithelium in 11 of 18 specimens from normosmic patients and in 12 of 45 samples from anosmic patients. There was a significant difference in the proportion of specimens containing olfactory epithelium between both patients. In normosmic pateints, most of the biopsy samples contained normal-appearing olfactory tissue. However, two main patterns of histological findings were found in the olfactory mucosa of anosmic patients: First, the olfactory receptor cells were remarkably decreased in their number. Second, the orderly arrangement of cells characteristic of normal olfactory epithelia was lost, demonstrating degenerative appearance.
CONCLUSION
These data suggest that olfactory epithelium can be degenerated even in chronic sinusitis and thereafter extensively replaced with respiratory epithelium, resulting in increased sampling error. Moreover, unimproved olfactory deficit following sinus surgery may be due to the abnormalities observed at the olfactory epithelium level.