Analysis of clinicopathological and molecular biological characteristics of patients with plasma cell tumor / 白血病·淋巴瘤

ABSTRACT

Objective:To investigate the clinicopathological and molecular biological characteristics of patients with plasma cell tumor.Methods:The data of bone marrow fluid, bone marrow tissue, peripheral blood and urine specimens of 84 patients with plasma cell tumor from January 2016 to October 2018 in Shanxi Provincial People's Hospital were collected. Bone marrow fluid was examined by using bone marrow smear, karyotype analysis, fluorescence in situ hybridization (FISH), immunophenotyping, and next-generation sequencing (NGS). In addition to the observation of cell morphology, peripheral blood together with urine specimens was also determined by using immune-fixation electrophoresis and free light chain examination. Bone marrow tissue was used to observe the structure and fibrosis of bone marrow, and relevant histochemistry and immunohistochemistry was also performed.Results:Among 84 patients with plasma cell tumor, 2 patients (2.4%) were monoclonal gammopathies of un-determined significance (MGUS), 78 patients (92.8%) were multiple myeloma (MM) (38 cases were IgG Kappa type, 33 cases were IgG Lambda type, 2 cases were IgA Kappa type, 1 case was IgA Lambda type, 3 cases were light chain type, 1 case was non-secretory type), 3 cases (3.6%) were Waldenstrom macroglobulinemia (WM), and 1 case (1.2%) was non-secretory myeloma (NSM). The proportion of abnormal plasma cells detected by bone marrow smear was 0.132-0.676 in 81 patients, and the proportion of abnormal monoclonal plasma cells detected by flow cytometry (FCM) was 1.1%-52.4% in 79 patients. Immunohistochemistry and FCM detection of bone marrow showed positive or weak positive results of CD38 and CD138. Complex karyotype was rare in karyotype analysis. FISH examination showed IGH isolation in 24 patients (28.6%) and gene detection showed 1 case was positive IGH-CCND1 and 1 case was positive IGH-MAF; 1 case of free light chain examination was positive. The positive rate of NGS was lower.Conclusion:Most plasma cell tumors are IgG type, followed by IgA type. Light chain type of plasma cell tumors is rare, and IgM type and non-secretory type are extremely rare. The morphological manifestations of bone marrow smear cytology in different clone types are different.