Tumor markers--personal experience. Immunohistochemical markers for cancer diagnosis

Immunohistochemical tumor markers have been increasingly utilized for histopathological diagnosis. Major applications include: 1) Differential diagnosis of undifferentiated tumors, 2) identification of primary site of metastatic carcinoma of unknown primary, 3) analysis of tumor differentiation, 4) functional study of functioning tumors, and 5) assessment of tumor aggressiveness. Since many antigens can be detected in routinely processed formalin-fixed tumor tissues, immunohistochemistry is a very useful tool to analyze the relationship between phenotypic characteristics and morphology. It is expected that many more immunohistochemical markers will become available for histopathological diagnosis.