title: Enzyme and immunohistochemical studies on acute monocytic leukemia (FAB M5): proposal for a new immunohistochemical subclassification.
abstract: Using only morphological criteria as proposed by the French-American-British (FAB) Study Group, the subclassification of acute monocytic leukemia (FAB M5) into the categories M5a and M5b can be difficult. We therefore investigated 13 cases of well-established M5 leukemias. The results show that immunohistochemical techniques allow a better subdivision of the acute monocytic leukemias. The less-mature types are characterized by a focal lysozyme and a negative CD68 reaction, whereas the more differentiated types express a diffusely positive lysozyme and also a positive CD68 phenotype: a staining pattern also found in the rare true histiocytic lymphomas. We regard these results as a useful addition to the FAB classification.
authors.affiliation: Institut für Pathologie, Köhn, Deutschland.
authors.forename: R
authors.initials: R
authors.lastname: Budde
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D001853:Bone Marrow / Q000201:enzymology / Q000473:pathology; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D007948:Leukemia, Monocytic, Acute / Q000145:classification* / Q000201:enzymology / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009113:Muramidase / Q000378:metabolism; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D002265:Carboxylic Ester Hydrolases; D009113:Muramidase; C067980:CD68 antigen, human; D000097382:CD68 Molecule; C019873:chloroacetate esterase