Differential diagnosis of genitourinary tumors using monoclonal antibodies to intermediate filament proteins.

Definitive diagnosis of poorly differentiated and metastatic neoplasms may be impossible using conventional histologic criteria. Recent developments in cell biology and immunology now enable us to answer such difficult diagnostic problems. Several varieties of structural proteins can be identified in malignant cells using monoclonal antibodies. The composition of these proteins can yield information regarding the origin of a neoplasm. Intermediate filaments are one such family of structural proteins. By characterization of these proteins, using a panel of monoclonal antibodies, poorly differentiated tumors may be definitively classified as carcinomas, sarcomas, lymphomas, or neural tumors. This approach to tumor diagnosis is now applicable to difficult problems in clinical urology.