PAX5-positive plasma cell myeloma with t(9;14;11)(p13;q32;q13), a novel complex variant translocation of t(11;14)(q13;q32) and t(9;14)(p13;q32)

We describe herein the case of a 64-year-old man with a diagnosis of plasma cell myeloma (PCM). A chromosome analysis based on G-banding and spectral karyotyping revealed the following complex karyotype: 46,XY,del(3)(p?), t(4;15)(q31;q24),t(9;14;11)(p13;q32;q13),add(15)(q24),add(18)(q21). Fluorescence in situ hybridization (FISH) detected one signal each for the immunoglobulin heavy chain (IGH) and cyclin D1 ( CCND1 ) genes, and three fusion signals of IGH and CCND1 . FISH analysis of metaphase spreads revealed fusion signals on the derivative chromosomes 9, 11, and 14. Immunohistochemical analysis identified abnormal expression of CCND1 and PAX5 . PAX5-positive PCM is rare because the down-regulation of PAX5 is essential for the terminal differentiation of B cells into plasma cells. To the best of our knowledge, this is the first reported case of a novel complex variant translocation of t(11;14)(q13;q32) and t(9;14)(p13;q32).