Diagnostic Efficacy of^(18)F-FDG PET/CT in Detecting Bone Marrow Infiltration in Patients with Newly Diagnosed Diffuse Large B-Cell Lymphoma

Objective Diffuse large B-cell lymphoma(DLBCL)is often associated with bone marrow infiltration,and 2-deoxy-2-(18F)fluorodeoxyglucose positron emission tomography/computed tomography(^(18)F-FDG PET/CT)has potential diagnostic significance for bone marrow infiltration in DLBCL.Methods A total of 102 patients diagnosed with DLBCL between September 2019 and August 2022 were included.Bone marrow biopsy and^(18)F-FDG PET/CT examinations were performed at the time of initial diagnosis.Kappa tests were used to evaluate the agreement of^(18)F-FDG PET/CT with the gold standard,and the imaging features of DLBCL bone marrow infiltration on PET/CT were described.Results The total detection rate of bone marrow infiltration was not significantly different between PET/CT and primary bone marrow biopsy(P=0.302)or between the two bone marrow biopsies(P=0.826).The sensitivity,specificity,and Youden index of PET/CT for the diagnosis of DLBCL bone marrow infiltration were 0.923(95%CI,0.759-0.979),0.934(95%CI,0.855-0.972),and 0.857,respectively.Conclusion^(18)F-FDG PET/CT has a comparable efficiency in the diagnosis of DLBCL bone marrow infiltration.PET/CT-guided bone marrow biopsy can reduce the misdiagnosis of DLBCL bone marrow infiltration.

Occurrence of MYD88L265P and CD79B mutations in diffuse large b cell lymphoma with bone marrow infiltration:A case report

BACKGROUNDOver the past 20 years,we have gained a deep understanding of the biologicalheterogeneity of diffuse large B cell lymphoma(DLBCL)and have developed arange of new treatment programs based on the characteristics of the disease,bringing us to the era of immune-chemotherapy.However,the effectiveness andmolecular mechanisms of targeted-immunotherapy remain unclear in DLBCL.Targeted-immunotherapy may be beneficial for specific subgroups of patients,thus requiring biomarker assessment.CASE SUMMARYHere,we report a case of MCD subtype DLBCL with MYD88L265P and CD79Bmutations,considered in the initial stage as lymphoplasmic lymphoma(LPL)orWaldenstrom macroglobulinemia(WM).Flow cytometry supported this view;however,the immunohistochemical results of the lymph nodes overturned theabove diagnosis,and the patient was eventually diagnosed with MCD subtypeDLBCL.The presence of a monoclonal IgM component in the serum and infiltrationof small lymphocytes with a phenotype compatible with WM into the bonemarrow led us to propose a hypothesis that the case we report may have transformedfrom LPL/WM.CONCLUSIONThis highlights the possible transformation from WM to DLBCL,CD79B mutationmay be a potential biomarker for predicting this conversion.

Clinical characteristics and prognostic factors of patients with mature T-cell lymphoid malignancies： a single-institution study of 225 cases

Mature T-cell lymphoid malignancies comprise a group of heterogeneous diseases that vary in clinicopathological features, biological behavior, treatment response, and prognosis. Bone marrow （BM） infiltration is more commonly present in mature T-cell lymphoid malignancies compared with their B-cell counterparts and hence important for differential diagnosis. In this study, clinical characteristics and prognostic factors were analyzed in 225 patients with mature T-cell lymphoid malignancies treated in a single institution. These included 29 cases of T-cell lymphoproliferative disorders （T-LPD, all with BM infiltration） and 196 cases of T-/natural-killer-cell lymphoma （T/NKCL, 56 with BM infiltration and 140 without BM infiltration）. The estimated 5-year overall survival （OS） rates of T-LPD and T/NKCL were 96.6% and 37.3%, respectively. T-LPD patients were less likely to exhibit poor performance status, advanced disease stage, presence of B symptoms, or abnormal level of serum [^-2 microglobulin. With similar pathological characteristics, T/NKCL patients with BM infiltration showed significantly lower response rates and shorter OS than those without BM infiltration （P = 0.0264 and P 〈 0.0001, respectively）. Multivariate analysis indicated that poor performance status, advanced disease stage, elevated serum lactate dehydrogenase level, and BM involvement were independent unfavorable prognostic factors. The Glasgow Prognostic Score may be more efficient than the International Prognostic Index in predicting disease outcome in T/NKCL. In conclusion, clinical characteristics may be useful in more effectively stratifying patients with mature T-cell lymphoid malignancies.