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

Hypothesis: The bone destruction in cholesteatoma is multi-factoral. This study was undertaken to define the role of tumor necrosis factor-alpha (TNF-α) 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-α in aural cholesteatoma. An attemp was made in this study to show a correlation between TNF-α and cholesteatoma associated bone destruction by localizing TNF-α in cholesteatoma and measuring its serum level. Methods: Serum TNF-α levels were measured in 20 patients with cholesteatoma of temporal bone and histochemical staining was used to localize TNF-α in pathologic tissue excised at surgery. Results: Serum TNF-α levels in patients with cholesteatoma were significantly higher than in controls. In addition, TNF-α 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-α levels. The TNF-α was localized in various layers of cholesteatoma epithelium using indirect immunoperoxidase staining. Conclusion: TNF-α is one of the cytokines produced by cholesteatoma that may be an important mediator of bone destruction associated with cholesteatoma. TNF-α has been localized in various layers of cholesteatoma and exerts a locally destructive effect on bone. Serum TNF-α levels are related to the extent of bone destruction.