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Cyclooxygenase-2 expression in Warthin's tumour.

OBJECTIVES
To determine whether cyclooxygenase-2 (COX-2) is overexpressed in Warthin's tumours, and to characterize its pattern of expression.


METHODS
Twenty-one paraffin-embedded Warthin's tumour specimens were analysed by immunohistochemical staining for expression of human COX-2. Semi-quantitative analysis of the staining was performed.


RESULTS
In all of the specimens, we found that there was overexpression of COX-2 within the epithelial component of the tumours, with no expression in the lymphoid components. There was also overexpression of COX-2 in the salivary duct system of normal parotid tissue.


CONCLUSIONS
Our results suggest that COX-2 is up-regulated in the epithelial component of Warthin's tumours. Our findings support the hypothesis that Warthin's tumours originate from heterotopic ductal epithelial cells of the parotid gland. The role of COX-2 expression in the pathogenesis of Warthin's tumours remains to be determined.