A 34-year-old man presents with symptoms of fatigue, weakness, nose bleeds, and palpitations with exertion. On examination he is pale, blood pressure 110/70 mm Hg, pulse 100/min, heart sounds are normal, lungs are clear, and he has multiple petechiae and bruises on his legs. His blood count is abnormal: hemoglobin 8.5 g/dL white blood cells (WBCs) 4000/mL, platelets 50,000/mL, and there are blast cells in the peripheral blood. He is diagnosed with acute promyelocytic leukemia (AML-M3). Which of the following is a characteristic of this acute myelogenous leukemia? (See Fig. below.)