 We describe an unusual case of acute promyelocytic leukemia with +der(17)t(15;17) as the additional cytogenetic abnormality and with t(15;17) defined by fluorescence in situ hybridization (FISH) using a PML/RARA dual color, dual fusion translocation probe.     ///    "By performing a step-by-step, complementary approach to evaluate unusual chromosomal abnormalities, we detected RARA/PML fusion on a marker chromosome similar to chromosome 17.. "