Distinctive AgNOR patterns of myeloid and lymphoid blasts in acute leukemia

Bone-marrow aspiration smears of 38 cases of acute leukemia (19 acute lymph oblastic leukemia, 19 acute nonlymphocytic leukemia) were stained for argyr ophilic nucleolar organiser regions (AgNOR), AgNOR were assessed numericall y and morphologically, There were highly significant differences in AgNOR m orphology between acute lymphoblastic leukemia and acute nonlymphocytic leu kemia ANLL: lymphoblast AgNORs were usually small (<3 mu m) "dots/chips," w hereas myeloblasts showed larger "blebs," or a combination of the two types (complex structures). AgNOR number was significantly less in acute lymphob lastic leukemia. In acute nonlymphocytic leukemia cases, AgNOR number also showed direct correlation with Ki67 reactivity of leukemic blasts. Am, J. H ematol. 61:149-152, 1999, (C) 1999 Wiley-Liss, Inc.