Rare expression of the c-erbB-2 oncoprotein in salivary gland tumors: an immunohistochemical study.

An immunohistochemical study of c-erbB-2 oncoprotein expression was carried out on 201 cases of primary salivary gland tumors, using a polyclonal antibody, raised to the intracytoplasmic domain of the c-erbB-2 oncogene product. An intense membrane reactivity was observed in one case of sialocarcinoma transformed from pleomorphic adenoma (n = 8) and one case of mucoepidermoid carcinoma (n = 22). A comparative histopathologic evaluation of c-erbB-2 positive tumors showed marked variation in cell size, nuclear pleomorphism, multinucleation, a high mitotic rate and increased lymphoid cell infiltration and an aggressive clinical course with poor survival. The results indicate that c-erbB-2 oncoprotein is rarely expressed in malignant salivary gland tumors. However, the overexpression appears to have a distinct histopathologic feature, but a larger study incorporating histopathology and clinical data would be necessary to correlate the significance of c-erbB-2 oncogene product in salivary malignant tumors.