Avet-Loiseau Hervé, Garand Richard, Lodé Laurence, Robillard Nelly, Bataille Régis
Laboratory of Hematology, University Hospital, Nantes, France.
Semin Oncol. 2003 Apr;30(2):153-5. doi: 10.1053/sonc.2003.50053.
Even though the diagnosis of Waldenstrom's macroglobulinemia WM is usually clear, the differential diagnosis with IgM multiple myeloma (MM) might be possible. IgM MM is usually characterized by the accumulation of small mature plasma cells within the bone marrow, and the detection of a monoclonal IgM in the serum. However, in contrast with classical MM, IgM MM is rarely associated with these patients' extensive osteolytic lesions. We analyzed eight cases of IgM MM. None presented with extensive bone lesions. All cases were characterized by the presence of small mature plasma cells within the bone marrow. Molecular cytogenetic analysis revealed a t(11;14) in seven of the eight cases. In contrast, a similar analysis in 17 WM cases failed to detect any t(11;14) cases. We performed further fluorescence in situ hybridization (FISH) experiments, focused on the 14q32 region, and especially on the IgH gene. In contrast to MM (in which illegitimate IgH rearrangements are common), we did not detect any abnormality in the WM cases. In conclusion, even though the cells of origin in WM and MM are mature heavily mutated cells, they differ by the IgH gene rearrangements. Especially in IgM MM, the search for t(11;14) might be useful in difficult cases to discriminate with WM.
尽管华氏巨球蛋白血症（WM）的诊断通常较为明确，但仍有可能与IgM型多发性骨髓瘤（MM）进行鉴别诊断。IgM型MM通常表现为骨髓内小的成熟浆细胞积聚，以及血清中检测到单克隆IgM。然而，与经典MM不同的是，IgM型MM很少与这些患者的广泛溶骨性病变相关。我们分析了8例IgM型MM病例。无一例出现广泛的骨病变。所有病例的特征均为骨髓内存在小的成熟浆细胞。分子细胞遗传学分析显示，8例中有7例存在t(11;14)。相比之下，对17例WM病例进行的类似分析未检测到任何t(11;14)病例。我们进行了进一步的荧光原位杂交（FISH）实验，重点关注14q32区域，尤其是IgH基因。与MM（其中非法IgH重排很常见）不同，我们在WM病例中未检测到任何异常。总之，尽管WM和MM的起源细胞都是成熟的高度突变细胞，但它们在IgH基因重排方面存在差异。特别是在IgM型MM中，寻找t(11;14)在与WM鉴别诊断困难的病例中可能有用。
