Misra Sunayana, Singh Anu, Kumar Vijay
Department of Pathology, ABVIMS and Dr. RML Hospital, Delhi, India.
J Cancer Res Ther. 2024 Apr 1;20(3):1026-1028. doi: 10.4103/jcrt.JCRT_1362_20. Epub 2023 Dec 15.
Plasma cell myeloma (PCM) is a monoclonal gammopathy (MGM) characterized by proliferation of abnormal clone of plasma cells infiltrating the bone marrow with consequent end organ damage. The clonal plasma cells secrete a single clone of immunoglobulins (Ig) leading to presence of M-protein in the serum and/or urine. The M-protein is appreciated as a discrete band on serum protein electrophoresis (SPE) in the gamma globulin region, also called the M-band. Biclonal gammopathy (BGM) occurs due to neoplastic transformation of a plasma cell clone undergoing Ig class switching or due to an independent neoplastic transformation event yielding proliferation of unrelated plasma cell clones, therefore resulting in two distinct M-bands on SPE. It is, however, vital to distinguish a true BGM from an apparent one (MGM presenting with two distinct bands on SPE) so as to make an accurate diagnosis. Hereby, we report a case of a 61-year-old man, diagnosed with PCM and presenting with two discrete bands on SPE (simulating a BGM) which turned out to be monoclonal in nature.
浆细胞骨髓瘤（PCM）是一种单克隆丙种球蛋白病（MGM），其特征为异常浆细胞克隆增殖，浸润骨髓并导致终末器官损害。克隆性浆细胞分泌单一克隆的免疫球蛋白（Ig），导致血清和/或尿液中出现M蛋白。M蛋白在血清蛋白电泳（SPE）的γ球蛋白区表现为一条离散的条带，也称为M带。双克隆丙种球蛋白病（BGM）是由于经历Ig类别转换的浆细胞克隆发生肿瘤转化，或由于独立的肿瘤转化事件导致不相关浆细胞克隆增殖，因此在SPE上产生两条不同的M带。然而，将真正的BGM与看似是BGM的情况（MGM在SPE上呈现两条不同条带）区分开来对于做出准确诊断至关重要。在此，我们报告一例61岁男性病例，该患者被诊断为PCM，在SPE上呈现两条离散条带（类似于BGM），但结果显示本质上是单克隆的。
