Duplication 15q as the sole anomaly in an acute promyelocytic leukemia patient without t(15;17)

We present a unique chromosomal abnormality found in a patient with acute myeloblastic leukemia of French–American–British subtype M3. The patient was referred for an evaluation of a chromosomal anomaly exclusively associated with FAB M3 or acute promyelocytic leukemia: a translocation between chromosomes 15 and 17, t(15;17)(q22;q21.1). Neither t(15;17) nor rearrangement of RARα was detected by routine G-banded chromosome as well as fluorescence in situ hybridization analysis using the commercial dual-color PML/RARα translocation probe and the RARα probe, a break apart rearrangement dual-color probe. Instead of the typical rearrangement between chromosomes 15 and 17, all cells analyzed had a duplication of the segment of chromosome 15 between bands 15q15 and 15q26.