![A 76-year-old woman presented generalized weakness and easy bruising. Her laboratory values showed a white blood cell count of 15.1 × 109/L, hemoglobin 90 g/L, and platelets 19 × 109/L with 85% circulating abnormal promyelocytes, many of which with Chediak-Higashi like giant granules (panels A,B: Wright stain, original magnification ×1000 for both panels). The promyelocytes were uniformly and strongly positive for cytochemical myeloperoxidase stain (panel C: original magnification ×1000). No Auer rods were seen. Other laboratory values were fibrinogen 1.58 g/L and d-dimer >20 mg/L. Bone marrow revealed 71% promyelocytes with similar morphological features (panels D,E: Giemsa-Wright stain, original magnification ×1000 for both panels; panel F: myeloperoxidase with counterstain, original magnification ×1000). Flow cytometry study demonstrated a population of aberrant myeloid precursors, positive for CD13, CD33, CD34 (subset), CD38, CD64, CD117 (subset), and CD123, and negative for HLA-DR, and T- and B-lineage markers. Fluorescence in situ hybridization study revealed a clone with PML/RARA rearrangement, whereas molecular analysis detected the PML-RARA bcr3/short fusion transcript, establishing the diagnosis of acute promyelocytic leukemia with PML-RARA. Cytogenetics detected 46, XX; t(15;17)(q22;q21)[18]. Patient was treated with all trans retinoid acid, arsenic trioxide, and idarubicin, and a morphological remission was achieved in the bone marrow.](https://ash.silverchair-cdn.com/ash/content_public/journal/blood/139/1/10.1182_blood.2021013975/4/m_bloodbld2021013975f1.png?Expires=1733751585&Signature=WjeYCtPk~m7uA1VVPZ9pk8baD1ZiVc8dJA04QMQko4H0kTQAtzcf3GeLzYAoSiw~upgz9Co7A~IcsEhMCa~N-CJfJc9uoLs0AkHp3jt2hCFymNLqGjB5Yxw2WFTTw2mhLf7WGY4TeQvLbs5XDuA26lQmCJRJPEYdUn~fsxOcqxNhY0eqIK58WpTFqgT7ADeIorE3OsbJJbcl0rU8h4S90xC~BedOA7qpSipz8vrgpNaUpheYX4SHwChvzugKYN6TPJ49N1NtY117XOiblxOOrH4epOVIRcDOLkGF3-NQdQqohgBAZX9Iwo-I5miLP7OuYRmJgS9-Y8H1ZNVKnBV~xg__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
A 76-year-old woman presented generalized weakness and easy bruising. Her laboratory values showed a white blood cell count of 15.1 × 109/L, hemoglobin 90 g/L, and platelets 19 × 109/L with 85% circulating abnormal promyelocytes, many of which with Chediak-Higashi like giant granules (panels A,B: Wright stain, original magnification ×1000 for both panels). The promyelocytes were uniformly and strongly positive for cytochemical myeloperoxidase stain (panel C: original magnification ×1000). No Auer rods were seen. Other laboratory values were fibrinogen 1.58 g/L and d-dimer >20 mg/L. Bone marrow revealed 71% promyelocytes with similar morphological features (panels D,E: Giemsa-Wright stain, original magnification ×1000 for both panels; panel F: myeloperoxidase with counterstain, original magnification ×1000). Flow cytometry study demonstrated a population of aberrant myeloid precursors, positive for CD13, CD33, CD34 (subset), CD38, CD64, CD117 (subset), and CD123, and negative for HLA-DR, and T- and B-lineage markers. Fluorescence in situ hybridization study revealed a clone with PML/RARA rearrangement, whereas molecular analysis detected the PML-RARA bcr3/short fusion transcript, establishing the diagnosis of acute promyelocytic leukemia with PML-RARA. Cytogenetics detected 46, XX; t(15;17)(q22;q21)[18]. Patient was treated with all trans retinoid acid, arsenic trioxide, and idarubicin, and a morphological remission was achieved in the bone marrow.
Awareness of this rare morphological variant of acute promyelocytic leukemia will help promptly establish the diagnosis.
A 76-year-old woman presented generalized weakness and easy bruising. Her laboratory values showed a white blood cell count of 15.1 × 109/L, hemoglobin 90 g/L, and platelets 19 × 109/L with 85% circulating abnormal promyelocytes, many of which with Chediak-Higashi like giant granules (panels A,B: Wright stain, original magnification ×1000 for both panels). The promyelocytes were uniformly and strongly positive for cytochemical myeloperoxidase stain (panel C: original magnification ×1000). No Auer rods were seen. Other laboratory values were fibrinogen 1.58 g/L and d-dimer >20 mg/L. Bone marrow revealed 71% promyelocytes with similar morphological features (panels D,E: Giemsa-Wright stain, original magnification ×1000 for both panels; panel F: myeloperoxidase with counterstain, original magnification ×1000). Flow cytometry study demonstrated a population of aberrant myeloid precursors, positive for CD13, CD33, CD34 (subset), CD38, CD64, CD117 (subset), and CD123, and negative for HLA-DR, and T- and B-lineage markers. Fluorescence in situ hybridization study revealed a clone with PML/RARA rearrangement, whereas molecular analysis detected the PML-RARA bcr3/short fusion transcript, establishing the diagnosis of acute promyelocytic leukemia with PML-RARA. Cytogenetics detected 46, XX; t(15;17)(q22;q21)[18]. Patient was treated with all trans retinoid acid, arsenic trioxide, and idarubicin, and a morphological remission was achieved in the bone marrow.
Awareness of this rare morphological variant of acute promyelocytic leukemia will help promptly establish the diagnosis.
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