Expression of rasp2l, c-erbB-2, and p53 and Implications on Biological Behaviour of Parotid Pleomorphic Adenoma

Abstract

Objective: To examine the expression of rasp2l, c-erbB-2, and p53 in parotid pleomorphic adenoma in an attempt to improve the predictability of the tumour's biological behaviour in relation to borderline malignancy.Materials and Methods: Twenty five benign and 17 malignant parotid pleomorphic adenoma specimens were collected from the files of 4 institutions during a 16-year period (1980 to 1986). Re-examination of specimens was done using immunohistochemical techniques. Immuno-expression was graded according to the following criteria: 0 = negative; +1 = focal (<20%); +2 = heterogenous (20-50%), and +3 = diffuse (>50%). Heterogenous and diffuse were considered to be overexpression.Results: Significant expression of rasp21 (88.1 %), c-erbB-2 (92.8%), and p53 (97.6%) was noted. Sensitivity and negative predictive value were 100%. However, specificity was 50% and false positivity was encountered in benign tumours only.Conclusions: rasp2l, c-erbB-2, and p53 expression in parotid pleomorphic adenoma may point to a role in predicting borderline malignancy.