Detection of PML-RAR alpha fusion transcript in Ph positive leukemia with acute promyelocytic phenotype lacking the t(15;17) cytogenetic abnormality.

A 39-year-old woman was diagnosed with acute promyelocytic leukemia (APL) with disseminated intravascular coagulation syndrome. The hematologic examination showed a morphologic, cytochemical, and immunophenotypic picture typical of an APL, with a marked leukocytosis and a mixed population of hypergranular and microgranular promyelocytes. The cytogenetic analysis showed a 46,XX,t(9;22) karyotype, without any alterations of chromosomes 15 and 17. The t(15;17) translocation was not evident in FISH experiments, while a molecular analysis revealed the presence of a PML-RAR alpha chimera.