PubMed2026
BACKGROUND: Multiple myeloma (MM) and diffuse large B-cell lymphoma (DLBCL) are B-cell malignancies that rarely coexist in a single patient, presenting significant diagnostic and therapeutic challenges. While MM primarily involves clonal plasma cells, DLBCL is an aggressive lymphoid neoplasm. Investigating shared genetic mutations and understanding their clinical relevance in both cancers could provide novel insights into their pathogenesis and underlying molecular mechanisms, thereby informing future translational research. MATERIALS AND METHODS: A case report was conducted on a 52-year-old male who presented with abdominal pain and anemia. Imaging revealed lymphadenopathy, and biopsy confirmed high-grade DLBCL with concurrent bone marrow involvement suggestive of MM. Laboratory tests identified monoclonal IgM gammopathy, and the patient was treated with R-CHOP (Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, and Prednisone) chemotherapy for DLBCL followed by autologous stem cell transplantation (ASCT) for MM relapse. A systematic review of the literature was performed using PubMed, Scopus, and Web of Science databases to identify cases of patients diagnosed with both MM and DLBCL. Data on patient demographics, clinical features, treatment regimens, and outcomes were extracted. Additionally, bioinformatics analysis was conducted using publicly available genomic data from cBioPortal and IntOGen to identify driver gene mutations in MM and DLBCL. Functional and pathway enrichment analysis was performed with KEGG and Gene Ontology (GO) databases. RESULTS: The case report highlighted a complex clinical course where the patient initially responded well to R-CHOP chemotherapy for DLBCL, achieving remission, but later relapsed with MM, treated with ASCT and lenalidomide. The systematic review revealed 14 eligible studies in which MM and DLBCL often occur in older patients, either simultaneously or sequentially, with variable treatment responses, including complete remission, partial remission, or relapse. The bioinformatics analysis identified several shared function and cancer-related pathways between two cancers including interleukin and cytokine-mediated signaling pathways, regulation of cell cycle, neurotrophin signaling pathway, FOXO signaling pathway, Epstein Barr virus infection, and viral carcinogenesis. CONCLUSION: This study provides valuable insights into the dual occurrence of MM and DLBCL, emphasizing the importance of tailored treatment approaches. The driver mutations identified highlight overlapping oncogenic pathways rather than implying a shared clonal origin, and may inform future studies exploring their biological and clinical implications. Further research into these shared molecular mechanisms could lead to more effective treatments for patients with coexisting MM and DLBCL.