Bacterial microcolonies exist within the sphenoid bone in chronic rhinosinusitis and healthy controls

Abstract

Background: Some patients with chronic rhinosinusitis (CRS) exhibit thickening of the sinus bones that has been termed osteitis. The histopathology and microbiology of these changes have not been fully described. The aim of this study was to look for the presence of bacteria and immune cells within samples of bone from patients with and without CRS and correlate these findings to radiological findings.

Methods: Bone on the anterior face of the sphenoid was examined radiologically and histologically in 8 patients with CRS with nasal polyposis, 8 patients with CRS without polyposis, and 6 control patients with pituitary adenomas and normal sinuses. Bone thickness and density were measured by computed tomography (CT) scanning. Bone samples were collected intraoperatively and 20 tissue sections were analyzed for each patient. Bacteria were identified by Giemsa and Gram stains. Immune cells were identified by conventional histology and immunohistochemistry.

Results: Small colonies of bacteria were identified within the bone in 3 of 16 CRS patients and 2 of 6 control subjects (p = 0.6). Isolated immune cells were identified within the bone in 3 of 16 CRS patients and 2 of 6 control subjects (p = 0.6) but both bacteria and immune cells occurred together in only 1 case. The presence of bacteria or immune cells within bone samples did not correlate with either bone thickness or bone density.

Conclusion: This study describes the presence of bacteria and immune cells within a minority of CRS patients and normal controls. The bacterial microcolonies identified do not appear to be the cause of the bone changes seen in many CRS patients.