RESUMO
Acute promyelocytic leukemia (APL) is a type of acute myeloid leukemia (AML) characterized by the presence of t(15;17)(q22;q21) translocation leading to fusion between PML and RARa gene. Treatment combining all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) has dramatically improved the prognosis of APL. We report a rare finding of primary clone of t(15;17) followed by a sequential clonal evolution of additional derivative chromosome 6 formation by a two hit mechanism. Our case showed a good clinical response with a four years and nine months event free survival after ATRA and ATO combination therapy in spite of existence of three chromosomal abnormalities stating that targeted therapy overcomes the adverse effects of additional genetic markers. However, close monitoring with assessment for long term prognostic behavior is required.
RESUMO
A spectrum of Cellular homolog of the v-myc oncogene (cMYC) alterations such as translocation, overexpression, mutation, and amplification plays an important role in lymphomagenesis, particularly in high-grade lymphomas, and are associated with prognostic significance. Accurate identification of cMYC gene alteration is important for diagnostic, prognostic, and therapeutic implications. With the application of different FISH (fluorescence in situ hybridization) probes that helped overcome the analytical diagnostic challenges as a result of variant patterns, we report rare, concomitant, and independent gene alterations in cMYC and Immunoglobulin heavy-chain gene (IGH) with detailed characterization of its variant rearrangement. Short-term follow-up post R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) therapy seemed to be favorable. Accumulation of many more literature studies on such cases with their therapeutic implications would lead to the categorization of these cases as a separate subclass in large B-cell lymphomas followed by molecular targeted therapy.