[Auer rods-positive neutrophils observed at diagnosis increased after remission induction in patient with acute promyelocytic leukemia].

50-year-old male was admitted to our hospital because of gingival bleeding and fever in August 1987. The leukocyte count was 13,300/microliters with 80.5% leukemic promyelocytes and bone marrow was hypercellular with 86.4% leukemic promyelocytes. A small number of mature neutrophils containing Auer rods were seen in bone marrow. On a diagnosis of acute promyelocytic leukemia and treated with induction chemotherapy consisting of behenoyl-arabinofuranosyl cytosine (BHAC), daunorubicin, 6-mercaptopurine (6-MP) and prednisolone (PSL) was reformed. After cytoreduction, leukemic cells reappeared in the peripheral blood, concomitant with mature neutrophils having Auer rods. Vitamin D3 was not effective as a differentiation inducing agent. Complete remission was obtained in November 1987 by the reinduction chemotherapy consisting of BHAC, aclarubicin, 6-MP and PSL. In this case, neutrophils with Auer rods might have been derived from the leukemic clone and differentiation of leukemic promyelocytes by intensive chemotherapy.