Immunoexpression of c-erbB-2 and p53 in benign and malignant salivary neoplasms with myoepithelial differentiation.

AIM To evaluate whether the immunoexpression of c-erbB-2 and p53 is involved in the pathogenesis and progression of salivary tumours with myoepithelial differentiation. METHODS 233 tumours from 211 patients were studied. These included 76 primary and 24 recurrent adenocarcinomas (polymorphous low grade adenocarcinoma, 13; epithelial-myoepithelial carcinoma, 19; adenoid cystic carcinoma, 56; and basal cell adenocarcinoma, 12) and 133 pleomorphic adenomas and myoepitheliomas, 96 being primary and the remaining recurrent tumours. All cases were formalin fixed and paraffin wax embedded. A StrepABC peroxidase method and polyclonal c-erbB-2 and p53 specific antisera were used. RESULTS Cell membrane staining of c-erbB-2 was not found in any benign or malignant tumour. There was p53 protein accumulation in one primary and one recurrent pleomorphic adenoma and in 10 adenocarcinomas (polymorphous low grade adenocarcinoma, one; epithelial-myoepithelial carcinoma, one; adenoid cystic carcinoma, five; and basal cell adenocarcinoma, three), three of them being recurrences. CONCLUSIONS The c-erbB-2 and p53 proteins are not involved in the pathogenesis of pleomorphic adenoma and myoepithelioma and do not constitute biomarkers in assessing the risk of recurrence. c-erbB-2 is not involved in the genesis of low grade salivary neoplasia with myoepithelial differentiation. The percentage of this type of neoplasia with p53 accumulation is low (10%) and does not appear to be related to tumour recurrence.