Magic mirror in my hand, which is the lineage in the end? A case of acute leukemia with hand-mirror cells.

A 75-year-old man with a diagnosis of chronic myelomonocytic leukemia evolved with asthenia and worsening cytopenias. A complete blood count showed hemoglobin 9.2 g/dL, neutrophils 0.5 3 10/L, monocytes 1.3 3 10/L, and platelets 20 3 10/L. Peripheral blood smear revealed 35% blast cells with a moderate nuclear:cytoplasmic ratio and one or more nucleoli. A high proportion of blast cells showed a hand-mirror morphology characterized by a cytoplasmic tail extending out from one pole of the nucleus (panels A and B, arrows) and harboring a few azurophilic granules and Auer rods (panels A and B, arrowheads). Bone marrow aspirate revealed 34% blast cells with similar morphology. Flow cytometry analysis confirmed an increased number of myeloblasts (CD34, CD117, CD13, MPO). Cytogenetic analysis demonstrated 13q deletion in 3 metaphases—46,XY, del(13)(q12q22)[3]/46,XY[17].