Primary bone marrow diffuse large B cell lymphoma (DLBCL) is an independent pathologic type with a poor prognosis when treated with standard chemoimmunotherapy. Generally, rituximab-based high-dose chemotherapy regimens such as dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (DA-EPOCH) can be administered to young patients, followed by autologous stem cell transplantation. For elderly patients, the rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) regimen is well tolerated, but it is an insufficient induction therapy for this group. Herein, we reported an elderly patient diagnosed with primary bone marrow DLBCL, germinal center B-cell-like subtype. Considering tolerance, the R-CHOP regimen was administered. However, his disease progressed after two treatment cycles. Then, the rituximab, gemcitabine, dexamethasone, cisplatin, lenalidomide regimen was administered, but the patient still experienced disease progression. Subsequently, the histone deacetylase (HDAC) inhibitor chidamide and Bruton’s tyrosine kinase (BTK) inhibitor ibrutinib were concurrently administered, and the patient achieved complete remission. We found that the response of primary bone marrow DLBCL to chemotherapy was poorer than that of de novo DLBCL. High-dose chemotherapy regimens such as DA-EPOCH should be administered to young patients in combination with rituximab. For elderly patients, new targeted drugs such as HDAC and BTK inhibitors appear to produce favorable outcomes.
Role of macrophages in bone marrow cavity formation