Cytochemistry and immunochemistry in hematologic diagnoses.

With new understanding in the biology of hematologic diseases and the rapid progress in their treatment, it is essential to diagnose and classify the various hematologic diseases with great precision. In recent years, the cell type-specific markers have been used successfully in cell identification for more precise diagnosis and classification of neoplastic diseases. The cytochemical method for cell identification is simple and is most useful for disorders of granulocytes, monocytes/histiocytes, hairy cells, and mast cells. The immunochemical methods are particularly useful in identifying the cell types, the clonality, and the maturation of cells in the lymphoid disorders. They are also helpful in the diagnosis of disorders of the erythroid and megakaryocytic cells, as well as nonhematopoietic neoplasms with marrow involvement.