In the context of leukocytosis due to increased number of neutrophils and their precursors, with significant dysgranulopoiesis and no or minimal basophilia and no or minimal monocytosis, the typical feature of "clumped" chromatin, in irregularly coarse compacted nuclei, should lead to suspect the diagnosis of atypical chronic myeloid leukemia.
Keywords: aCML; clinical case; hematology; leukocytosis; peripheral blood smear.