V.K.001

(A–C) Marrow films. Marrow has a large population of promyelocytes, which represents the cohort of myeloid cells recovering from agranulocytosis. The alteration may be accompanied by anemia and the marrow may raise concern about promyelocytic leukemia. Over a short period of observation neutrophils begin to enter the blood and marrow granulopoiesis is restored to a normal distribution of precursor cells.