Zhao Yue, Petersen Philip, Stuart Sophie, He Jiaqi, Ju Yaping, Carrillo Luis F, Carlsen Eric D, Xie Yi, Ghezavati Alireza, Siddiqi Imran, Zhang Ling, Wang Endi
From the Department of Pathology, College of Basic Medical Sciences, and the First Hospital, China Medical University, Shenyang, China (Zhao).
the Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles (Petersen, Stuart, He, Ju, Ghezavati, Siddiqi, Wang).
Arch Pathol Lab Med. 2025 Sep 1;149(9):822-830. doi: 10.5858/arpa.2024-0270-OA.
CONTEXT.—: The co-occurrence of plasma cell neoplasm (PCN) and lymphoplasmacytic lymphoma (LPL) is rare, and their clonal relationship remains unclear.
OBJECTIVE.—: To evaluate the clinicopathologic characteristics of concomitant LPL/PCN.
DESIGN.—: Retrospectively analyzed clinical and laboratory data of 14 cases.
RESULTS.—: Three patients initially presented with immunoglobulin (Ig) M paraprotein, 1 with IgG paraprotein, and 10 had simultaneous diagnoses of PCN and LPL. In 13 cases, flow cytometry detected both LPL and PCN in marrow biopsies. Furthermore, immunohistochemistry highlighted the 2 neoplastic populations, demonstrating an increased proportion of plasma cells and their expression of cyclin D1, CD56, and/or a non-IgM isotype restriction. All cases exhibited discordant heavy-chain isotypes between LPL and PCN. Thirteen of the 14 cases (92.9%) had concordant light-chain restrictions between the 2 neoplasms, and the remaining case (7.1%) showed discordant light-chain restrictions. Of the 12 patients with follow-up, 5 were treated with myeloma regimens, 2 with LPL regimens, 3 with combined therapy, and 2 with observation alone. Follow-up ranged from 2 to 146 months (median, 12.5 months). One patient died of PCN progression, one died of comorbidity, and 10 patients were alive with or without disease. Survival analysis showed no significant difference from the control.
CONCLUSIONS.—: The discordant heavy-chain isotype restrictions between PCN and LPL suggest biclonal B-cell neoplasms, which is supported by PCN's phenotypic distinction, such as the expression of cyclin D1 and/or CD56. However, our series exhibited a tendency toward concordant light-chain restrictions between the 2 neoplasms, raising the possibility that PCN may evolve from LPL through class switching.
浆细胞肿瘤（PCN）与淋巴浆细胞淋巴瘤（LPL）同时出现的情况罕见，它们的克隆关系仍不明确。
评估伴发LPL/PCN的临床病理特征。
回顾性分析14例患者的临床和实验室数据。
3例患者最初表现为免疫球蛋白（Ig）M副蛋白，1例为IgG副蛋白，10例同时诊断为PCN和LPL。13例中，流式细胞术在骨髓活检中检测到LPL和PCN。此外，免疫组化突出显示了这两种肿瘤细胞群，表明浆细胞比例增加及其细胞周期蛋白D1、CD56的表达和/或非IgM同种型限制。所有病例中LPL和PCN的重链同种型均不一致。14例中的13例（92.9%）在这两种肿瘤之间存在一致的轻链限制，其余1例（7.1%）表现为不一致的轻链限制。在12例有随访的患者中，5例接受了骨髓瘤治疗方案，2例接受了LPL治疗方案，3例接受了联合治疗，2例仅接受观察。随访时间为2至146个月（中位数，12.5个月）。1例患者死于PCN进展，1例死于合并症，10例患者存活，有无疾病状态不等。生存分析显示与对照组无显著差异。
PCN和LPL之间不一致的重链同种型限制提示双克隆B细胞肿瘤，这得到了PCN表型差异的支持，如细胞周期蛋白D1和/或CD56的表达。然而，我们的系列研究显示这两种肿瘤之间存在一致的轻链限制倾向，增加了PCN可能通过类别转换从LPL演变而来的可能性。
