2022 年 25 巻 3-4 号 p. 51-56
The reciprocal translocation t(11;14)(q13;q32) is frequently observed in multiple myeloma (MM) and related disorders. The aim of this study was to demonstrate that intraclonal heterogeneity occurs in t(11;14) itself. Fluorescence in situ hybridization (FISH) analyses of interphase nuclei were performed in 12 patients (10 with MM and 2 with other malignant monoclonal gammopathies) with t(11;14). An LSI IGH/CCND1 dual-color, dual-fusion translocation probe, which showed 2 standard types of signal pattern depending on the breakpoints on chromosome 11, was used for the detection of t(11;14). Although, 11 of 12 patients showed either of the 2 standard patterns, 1 patient showed both standard patterns, suggesting a coexistence of 2 clones with different patterns. Furthermore, all cases had clonal and non-clonal cells with various abnormal FISH signal patterns in addition to those with the standard pattern. These findings indicated that t(11;14) itself is susceptible to modification once it has occurred, followed by intraclonal heterogeneity through an evolutionary process of survival. The present study is helpful in understanding the biology of t(11;14) from the viewpoint of intraclonal heterogeneity.
