FIGURE 1. Bone marrow aspirate smear (Wright-Giemsa, 500x). Abundant blasts with frequently bilobed nuclei and moderate amounts of cytoplasm with abundant primary granules. No Auer rods were identified.
FIGURE 2. Bone marrow core biopsy (H&E, 100x). Markedly hypercellular marrow completely replaced by blasts.
FIGURE 3. Bone marrow core biopsy (H&E, 500x). Abundant blasts with bilobed nuclear and markedly granular cytoplasm.
FIGURE 4. Flow cytometry plots (ungated events, red = blasts). The blasts show typical immunophenotypic features of acute promyelocytic leukemia, including high side-scatter, CD33 and bright CD117 positivity. CD34 and HLA-DR were largely negative.
FIGURE 5. FISH studies showed 4 PML-RARA fusion signals.
FIGURE 6. Karyotyping performed on bone marrow aspirate showed tetraploidy and t(15;17)(q22;q12).