PMC7190808_01
Cytomorphology of bone marrow aspirates (A-C depict an overview of the slide; D-F show the cells at greater magnification; objective 63x). (A,D) Show a hypoplastic bone marrow after stem cell transplantation with up to 10% myeloblasts (marked by an arrow) resembling early relapse after allo-HSCT. Leukemic blasts display a basophilic cytoplasm frequently containing vacuoles. (B,E) (after one cycle of AZA) demonstrate a hypercellular marrow with ~50% of the previously described leukemic blasts (progressive disease). (C,F) (after two cycles of APA) show a normocellular marrow with an increased and left-shifted erythropoiesis, differentiated neutrophils and no evidence of an increased percentage of myeloblasts resembling complete remission.
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F1
Within routine follow-up bone marrow aspirate on day 89 after allo-HSCT, relapse of AML was diagnosed with an infiltration rate of 10% myeloid blasts in cytomorphological work-up (Figures 1A,D), which was confirmed by flow cytometry and chimerism analysis. Sustained pancytopenia seemed suspicious for refractory disease, which was confirmed by bone marrow aspirate with ~50% blasts in cytomorphology and chimerism of 45.5% (Figures 1B,E). Response assessment via bone marrow aspirate after the second cycle again demonstrated complete remission in cytomorphology (Figures 1C,F) and flow cytometry.