Ultrastructural Localization of Peroxidases in ‘Undifferentiated’Blasts during the Blast Crisis of Chronic Granulocytic Leukaemia

摘要: Summary. Twelve cases of Philadelphia chromosome positive chronic granulocytic leukaemia (CGL) in blast transformation have been investigated using ultrastructural peroxidase detection. In all cases, the leukaemic blasts were negative for myeloperoxidase on basis standard cytochemistry. nine a variable proportion contained activity detectable only by electron microscopy, permitting definition their myeloid nature. By distinct characteristics and localization, different activities recognized. Thus, several types identified: megakaryoblasts (MKB), basophil promyelocytes (BPM), with small granules containing (MyB), proerythroblasts (ProE). MKB predominant two present four mixed other blasts. BPM abundant one case seven cases. MyB identified as majority Three remained without any peroxidase. It is concluded that detection peroxidases value identification early Their high incidence simultaneous presence precursors suggest during crisis target cell frequently pluripotent stem cell.