PMC4764477_01
(A-F) - Features of the bone marrow aspirate/biopsy and Cytogenetics/FISH - A) Markedly increased blasts with open nuclear chromatin, inconspicuous nucleoli, and scant agranular basophilic cytoplasm. Dysplastic erythrocytes noted in the background (arrows) (arrows) (Wright-Giemsa stain, 500x) B) Sheets of immature medium size cells are seen interspersed with monolobated megakaryocytes (H&E, 500x) C-D) Immunohistochemistry showing strongly positive CD20 and TdT (Terminal deoxynucleotidyl transferase) (500x)E-F) Combined morphologic and FISH analysis - FISH with D5S721, D5S23/EGR1 probes. Arrow: dysplastic myelocytes and granulocyte, showing two green and one red signals, indicating 5q31 deletion; Arrow head: Blasts, showing two green and two red signals - normal pattern
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F1
Numerous small monolobated megakaryocytes were noted (Figure1A-B). Immunohistochemistry showed that the neoplastic cells expressed CD19, CD22, CD34, CD79a, CD20 and TdT (Figure 1C-D) but not CD3, CD10, CD61 and MPO. Combined morphologic/FISH analysis shows del(5q) only in dysplastic myelocytes and granulocytes, and not in the blasts (Figure 1E-F).