Coexistence of t(15;17) and t(15;16;17) detected by fluorescence in situ hybridization in a patient with acute promyelocytic leukemia: A case report and literature review

Acute promyelocytic leukemia (APL) is characterized by the t(15;17)(q22;q21), which results in the fusion of the promyelocytic leukemia (PML) gene at 15q22 with the retinoic acid α-receptor (RARA) gene at 17q21. The current study presents the case of a 54-year-old female with APL carrying the atypical PML/RARA fusion signal due to a novel complex variant translocation t(15;16;17)(q22;q24;q21), as well as the classical PML/RARA fusion signal. Subsequent array comparative genomic hybridization revealed somatic, cryptic deletions on 3p25.3, 8q23.1 and 12p13.2-p13.1, and a duplication on 8q11.2; however, no genetic material loss or gain was observed in the breakpoint regions of chromosomes 15, 16 or 17. To the best of our knowledge, this is the first report of the coexistence of two abnormal clones, one classical and one variant, presenting simultaneously in addition to cryptic chromosome segmental imbalances in an adult APL patient.