Structural Rearrangements of Trisomies Are a Risk Marker of Clinical Progression in Hyperdiploid Multiple Myeloma

Background: Hyperdiploid multiple myeloma (HMM) is being characterized by the presence of several trisomies and a low incidence of immuno globulin heavy chain rearrangements. It has not well defined what specific steps are associated with disease progression. We present two patients that showed some primary trisomies rearranged as a step of cytogenetic and clinical progression. This prompted us to review cytogenetic results from all patients referred to our hospital to assess the importance of this phenomenon in HMM. Patients and Methods: We carried out conventional cytogenetics in all patients. In four cases we also performed spectral karyotype (SKY) and arm-specific chromosome painting (ASP). Results: We demonstrate that in two patients some primary trisomies became along the disease course structurally altered and this coincided with clinical progression. We observed this phenomenon in more than 60% of HMM cases diagnosed at our laboratory. Conclusion: We propose structural rearrangements of trisomies as a biological marker of progression in HMM.