ABSTRACT
Objective:To investigate the value of bone marrow plasma cell morphology in the diagnosis and prognosis of plasma cell myeloma (PCM).Method:Observational study.Collect the bone marrow morphology image reports and corresponding monoclonal protein (M protein) identification results of 1071 patients [629 males and 442 females, Median age 62 (29, 93) years] diagnosed with PCM in the outpatient and inpatient departments of Beijing Chaoyang Hospital affiliated to Capital Medical University from January 1, 2017 to February 28, 2022. Combined with Durie‐Salmon(DS) and International Staging System (ISS) of 427 patients diagnosed with PCM and overall survival time (OS) of 436, summarize the relevant plasma cell morphological characteristics. Statistical methods include chi-square test, Kruskal-Walls test, Spearman correlation analysis and Kaplan-Meier survival analysis.Result:The bone marrow morphology reports showed that the typical morphological features of peripheral blood in 573 patients with PCM included plasma cells (40.84%), immature granulocytes (30.89%), rouleaux formation in erythrocytes (68.94%) and nucleated red blood cells (8.55%). The types of bone marrow plasma cells in 1 071 patients diagnosed with PCM included 372 (34.73%) plasmablasts, 674 (62.93%)immature plasma cells, and 25 (2.34%) mature plasma cells. There is a significant positive correlation between the number of bone marrow plasma cells (proportion of nuclear cells) and the concentration of IgG and IgA type, from M protein identification( r=0.55, r=0.60, P<0.01). The proportions of M protein types in 1 071 patients with PCM from high to low were IgG (45.75%), IgA (23.53%), light chain (19.61%), IgD (4.76%), non-secretory (4.3%), biclonal (1.78%), IgE (0.19%), IgM (0.08%). The typical characteristics of the bone marrow plasma cells in various M protein types included clustered distribution, different cell body sizes, inclusions in the cytoplasm, binuclear, polynuclear, and abnormal nuclear. The proportion of plasmablasts in DSⅢ stage was 44.81% (164/366), higher than 21.57% (11/51) in DSⅡstage, and the difference was statistically significant(χ 2=10.2, P<0.05). There was a significant positive correlation between the number of bone marrow plasma cells and DS and ISS stages( r=0. 0.23, r=0.30, P<0.01). The median OS of the PCM patients in the plasmablasts group was significantly shorter than that in the immature plasma cells group [56.0 (23.0, 101.8) months vs 75.9(31.6, 121.5) months, HR=1.42,95% CI 1.05-1.91, P=0.02]. The median OS of the PCM patients in the group of tumor plasma cells burden≥37.5% was shorter than that of the tumor plasma cells burden<37.5% [75.9 (21.4, 122.6)months vs 81.3 (36.6, 108) months, HR=1.54,95% CI 1.14-2.07, P<0.05]. Conclusion:The morphology and tumor burden of bone marrow plasma cells provide an important basis for the diagnosis of PCM and can be used as a prognostic indicator for patients with PCM.