Aural cholesteatoma: role of tumor necrosis factor-alpha in bone destruction.

HYPOTHESIS

The bone destruction in cholesteatoma is multifactorial. This study was undertaken to define the role of tumor necrosis factor-alpha (TNF-alpha) in bone destruction associated with cholesteatoma.

BACKGROUND

Tumor necrosis factor-alpha is an important inflammatory cytokine secreted by activated macrophages. It stimulates keratinocytes as an autocrine growth regulator. Few authors have localized TNF-alpha in aural cholesteatoma. An attempt was made in this study to show a correlation between TNF-alpha and cholesteatoma associated bone destruction by localizing TNF-alpha in cholesteatoma and measuring its serum level.

METHODS

Serum TNF-alpha levels were measured in 20 patients with cholesteatoma of temporal bone and histochemical staining was used to localize TNF-alpha in pathologic tissue excised at surgery.

RESULTS

Serum TNF-alpha levels in patients with cholesteatoma were significantly higher than in controls. In addition, TNF-alpha levels in patients with bone destruction were higher than in those without bone destruction. However, there was no correlation between age of the patient and serum TNF-alpha levels. The TNF-alpha was localized in various layers of cholesteatoma epithelium using indirect immunoperoxidase staining.

CONCLUSION

TNF-alpha is one of the cytokines produced by cholesteatoma that may be an important mediator of bone destruction associated with cholesteatoma. TNF-alpha has been localized in various layers of cholesteatoma and exerts a locally destructive effect on bone. Serum TNF-alpha levels are related to the extent of bone destruction.