IgM myeloma with t(4;14)(p16;q32)

Abstract

IgM multiple myeloma (MM) is a very rare and poorly characterized entity, which is estimated to comprise ≤0.5% of all cases of MM [ [1] De Gramont A. Grosbois B. Michaux J.L. Peny A.M. Pollet J.P. Smadja N. Krulik M. Debray J. Bernard J.F. Monconduit M. IgM myeloma: 6 cases and a review of the literature [in French]. Rev Med Interne. 1990; 11: 13-18 Crossref PubMed Scopus (20) Google Scholar ]. There are only limited published data on the clinicopathological characteristics of IgM MM. Some studies have suggested that it is associated with clinical and immunophenotypic features intermediate between those of MM and Waldenström macroglobulinemia (WM) [ 2 Kondo H. Yokoyama K. IgM myeloma: different features from multiple myeloma and macroglobulinaemia. Eur J Haematol. 1999; 63: 366-368 Crossref PubMed Scopus (15) Google Scholar , 3 Haghighi B. Yanagihara R. Cornbleet P.J. IgM myeloma: case report with immunophenotypic profile. Am J Hematol. 1998; 59: 302-308 Crossref PubMed Scopus (23) Google Scholar ]. Indeed, some studies have suggested that lymphadenopathy and hepatosplenomegaly may be seen in some patients—which are, of course, features more characteristic of lymphoma than of myeloma [ 1 De Gramont A. Grosbois B. Michaux J.L. Peny A.M. Pollet J.P. Smadja N. Krulik M. Debray J. Bernard J.F. Monconduit M. IgM myeloma: 6 cases and a review of the literature [in French]. Rev Med Interne. 1990; 11: 13-18 Crossref PubMed Scopus (20) Google Scholar , 4 Zarrabi M.H. Stark R.S. Kane P. Dannaher C.L. Chandor S. IgM myeloma, a distinct entity in the spectrum of B-cell neoplasia. Am J Clin Pathol. 1981; 75: 1-10 PubMed Google Scholar ]. Interphase FISH studies have been very informative in this disorder. MM is characteristically associated with translocations involving the immunoglobulin heavy chain (IgH) locus at 14q32. These are thought to occur through an error in isotype switch recombination and involve a number of partner chromosomes, most commonly 11q13 and 4p16 [ [5] Fenton J.A. Pratt G. Rawstron A.C. Morgan G.J. Isotype class switching and the pathogenesis of multiple myeloma. Hematol Oncol. 2002; 20: 75-85 Crossref PubMed Scopus (21) Google Scholar ]. In the context of IgM MM, Avet-Loiseau et al. [ [6] Avet-Loiseau H. Garand R. Lode L. Harousseau J.L. Bataille R. Translocation t(11;14)(q13;q32) is the hallmark of IgM, IgE, and nonsecretory multiple myeloma variants. Blood. 2003; 101: 1570-1571 Crossref PubMed Scopus (135) Google Scholar ] recently reported a t(11;14)(q13;q32) translocation in seven of eight cases assessed with interphase FISH. In contrast, IgH translocations appear to be very rare events in WM patients [ [7] Schop R.F. Fonseca R. Kuehl W.M. Van Wier S.A. Ahmann G.J. Price-Troska T. Bailey R.J. Jalal S.M. Qi Y. Kyle R.A. Greipp P.R. Waldenström macroglobulinemia neoplastic cells lack immunoglobulin heavy chain locus translocations but have frequent 6q deletions. Blood. 2002; 100: 2996-3001 Crossref PubMed Scopus (165) Google Scholar ].