Diagnosis of variant RARA translocation using standard dual-color dual-fusion PML/RARA FISH probes: An illustrative report.

Acute promyelocytic leukemia (APML) with variant RARa translocations comprises 1-2% of APML cases. However, the diagnosis of these cases is challenging as the routine practice includes fluorescence in situ hybridization (FISH) reverse transcription polymerase chain reaction targeting the PML and RARA genes to detect PML/RARA fusions. Here, we report a case highlighting the importance of atypical FISH signal patterns in standard dual-color dual-fusion PML/RARa FISH analysis complimented by karyotyping to detect these variant RARA translocations.