Division of Hematopathology, Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN, USA.
MHealth Fairview University of Minnesota Medical Center, USA.
Hum Pathol. 2024 Aug;150:86-96. doi: 10.1016/j.humpath.2024.06.012. Epub 2024 Jun 21.
Multiple myeloma (MM) is an incurable malignant plasma cell neoplasm, representing the second most common hematopoietic cancer. As plasma cell neoplasms are clonal and often secrete a monoclonal protein (M-spike), laboratory diagnosis is usually straightforward, especially when ancillary studies such as immunohistochemistry, flow cytometry, and protein electrophoresis are available in addition to microscopic examination. Despite the repertoire of diagnostic tools, rare cases pose diagnostic dilemmas, especially when reagent antibodies do not react as expected, extent of disease is patchy, or when disease occurs in unique age groups. In this retrospective study, we report a series of challenging diagnostic cases, discussing aberrant findings and comparing them to more classic counterparts. Twelve cases collected during routine clinical sign-out were reanalyzed and include examples of MGUS, classic multiple myeloma, t(11; 14) rearranged myeloma, minimal residual disease, AA and AL amyloidosis, truncated light chain, non-secretory and non-producer myeloma, biphenotypic myeloma, oligoclonal expansion after bone marrow transplant, and plasma cell leukemia in a young adult. This cohort showcases the diversity of atypical presentations of plasma cell neoplasms, and we highlight standardized approaches to workup to avoid diagnostic pitfalls.
多发性骨髓瘤（MM）是一种无法治愈的恶性浆细胞瘤，是第二大常见的血液系统恶性肿瘤。由于浆细胞瘤是克隆性的，并且经常分泌单克隆蛋白（M 峰），因此实验室诊断通常很直接，尤其是在显微镜检查之外还可以进行免疫组织化学、流式细胞术和蛋白质电泳等辅助研究时。尽管有一系列诊断工具，但罕见的病例仍会带来诊断难题，尤其是当试剂抗体的反应不符合预期、疾病的严重程度不均匀或疾病发生在独特的年龄组时。在这项回顾性研究中，我们报告了一系列具有挑战性的诊断病例，讨论了异常发现，并将其与更经典的病例进行了比较。在常规临床诊断过程中收集的 12 例病例被重新分析，包括 MGUS、经典多发性骨髓瘤、t（11；14）重排骨髓瘤、微小残留病、AA 和 AL 淀粉样变性、截断轻链、非分泌性和非产生性骨髓瘤、双表型骨髓瘤、骨髓移植后寡克隆扩增和年轻成人的浆细胞白血病。该队列展示了浆细胞瘤异常表现的多样性，我们强调了标准化的检查方法，以避免诊断陷阱。
