原发性骨淋巴瘤的液体活检指导治疗：venetoclax-Pola-R-CHP 和 CAR-T 实现分子缓解：一例病例报告

INTRODUCTION: Primary bone lymphoma (PBL) is a rare extranodal subtype of diffuse large B-cell lymphoma (DLBCL) that poses significant diagnostic challenges due to nonspecific clinical and radiological features. Molecular profiling and ctDNA monitoring now offer promising approaches for precision treatment and disease surveillance in DLBCL. CASE REPORT: A 54-year-old woman presented with persistent knee pain and multiple osteolytic lesions. After several nondiagnostic biopsies, open surgical biopsy confirmed germinal center B-cell-like DLBCL with high-risk molecular features (BCL2/MYC rearrangements, EZB subtype). The patient received molecularly guided therapy with Pola-R-CHP plus venetoclax, achieving complete metabolic remission. However, persistent MEF2B and TET2 mutations in ctDNA indicated MRD positivity, prompting consolidative CAR-T therapy (axicabtagene ciloleucel), after which she achieved sustained molecular remission with undetectable ctDNA. CONCLUSION: This case highlights three key aspects in managing PBL: the critical role of surgical biopsy for definitive diagnosis, particularly with concealed lesions; the value of molecular profiling in guiding targeted therapy; and the utility of ctDNA monitoring for MRD detection and treatment guidance. An integrated approach incorporating these strategies may improve outcomes for this rare lymphoma subtype. Background We report a very challenging case of bone lymphoma. This type of cancer originates primarily in the bones, is very rare, and poses significant difficulties in both diagnosis and treatment.The Problem The patient underwent multiple tests that failed to provide a definitive diagnosis, leading to a prolonged diagnostic process. Ultimately, through surgery and genetic testing, we identified this as a lymphoma with multiple high-risk genetic abnormalities.The Solution We developed a personalized treatment plan for her. Initially, targeted chemotherapy combined with specific drugs led to temporary improvement. However, more sensitive blood-based genetic testing detected remaining hidden enemies (minimal residual disease) in her body. Consequently, we decisively adopted the latest CAR-T cell immunotherapy as a consolidation treatment.Conclusion Ultimately, the patient achieved deep remission. This case demonstrates that integrating genetic technology, precision targeted therapy, and sensitive monitoring methods can bring hope to patients with even the most difficult-to-treat cancers.