[The value of immunohistochemistry in the study of tumors of the salivary glands].

Salivary gland tumors, despite the large number of studies which have been devoted to them, still pose many questions. Certain types are very difficult to classify, whilst in others the prognosis is uncertain and impossible to precisely identify. The problem of the histogenesis remains for many of them. This immunohistochemical study involving the principal types of salivary gland tumors used specimens previously fixed and mounted in paraffin wax. In certain cases immunohistochemistry is useful diagnostically thus making it possible to identify a myoepithelioma, and to draw the distinction between certain pleomorphic adenomas with an appearance likely to be a source of error and an adenocystic carcinoma. These methods are also useful in identifying the histogenesis of many salivary gland tumors, making it possible according to the individual case to demonstrate one or other variety of intermediate filaments, of functional markers, tumor markers or miscellaneous substances. In addition the histochemical study of cryostat sections of fresh tissue can be used in the case of lympho-epithelial tumors to define the precise nature of the lymphoid component, often a better approach to their histogenesis.