title: Abnormalities in granule formation in acute myelogenous leukemia.
abstract: Granule formation was investigated in differentiating neutrophils of a patient with acute myelogenous leukemia (AML) by means of the combined techniques of electron microscopy and peroxidase cytochemistry. Two important pathologic features were observed: first, an abnormal concentration and packaging of peroxidase into Auer rods in leukemic promyelocytes, and second, the presence of Auer rods surrounded by single-unit membranes in some mature polymorphonuclear leukocytes (PMN). An additional unexpected finding was the discovery of two distinct populations of PMN circulating concurrently; a minor (less than 5%) normal one that contained both peroxidase-positive azurophilic and peroxidase-negative specific granules and a major abnormal one characterized by the absence of specific granules. None of these abnormalities was observed during the two remissions of this patient's disease. During relapse a "hiatus leukemicus" occurred, which also revealed two populations of cells, a majority population of leukemic blasts, and a minority population of a few normal PMN. These findings documented several developmental abnormalities in the differentiating cells of myelogenous leukemia and also suggested that concurrent normal and abnormal populations of PMN may be a helpful diagnostic feature of a leukemic process.
mesh_terms: D000328:Adult; D003594:Cytoplasmic Granules / Q000648:ultrastructure*; D005260:Female; D006056:Golgi Apparatus / Q000648:ultrastructure; D006651:Histocytochemistry; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism / Q000473:pathology*; D009504:Neutrophils / Q000473:pathology* / Q000648:ultrastructure; D010544:Peroxidases / Q000378:metabolism; D012075:Remission, Spontaneous; D013194:Staining and Labeling
chemical_list: D010544:Peroxidases