Primary Bone Marrow Lymphoma: De Novo and Transformed Subtypes

Abstract

Diffuse large B-cell lymphoma (DLBCL) is well known for selectively involving certain extranodal locations such as the central nervous system (CNS), testes, and skin. DLBCL or high-grade B-cell lymphoma selectively involving the bone marrow is rare and has been sparsely reported in the medical literature. We report two cases of lymphoma presenting with primary bone marrow involvement without evidence of involvement of any other sites. The first case represents de novo DLBCL. The patient achieved complete remission with initial treatment, had a bone marrow-only relapse three years later, and achieved a second complete remission following non-transplant salvage therapy. The second case had findings consistent with “double hit” Richter’s transformation of chronic lymphocytic leukemia with translocation of c-MYC and BCL-2. This patient had an aggressive clinical course characterized by rapid progression with CNS involvement within three months resulting in the demise of the patient. These two cases represent two distinct subtypes of primary bone marrow lymphoma: de novo and transformed. Further research is necessary to gain a better understanding of this rare lymphoma entity and develop novel therapies.

Keywords:

• diffuse large B-cell lymphoma
• high-grade B-cell lymphoma with MYC and BCL-2 rearrangements
• bone marrow involvement
• cytopenias

Abbreviations

BTK, Bruton tyrosine kinase; CLL, chronic lymphocytic leukemia; CNS, central nervous system; CNS-IPI, central nervous system-international prognostic index; CR, complete remission; CSF, cerebrospinal fluid; DA-EPOCH-R, dose-adjusted etoposide, doxorubicin, vincristine, cyclophosphamide, prednisone, rituximab; DLBCL, diffuse large B-cell lymphoma; d-PBML, de novo primary bone marrow lymphoma; EBER, Epstein–Barr virus-encoded RNA; FDG, fluorodeoxyglucose; FISH, fluorescence in situ hybridization; HD, high-dose; HGBCL, high-grade B-cell lymphoma; ICC, International Consensus Classification; IESLG, International Extranodal Lymphoma Study Group; IHC, immunohistochemistry; ISH, in situ hybridization; IT, intrathecal; LDH, lactate dehydrogenase; MGUS, monoclonal gammopathy of undetermined significance; MRI, magnetic resonance imaging; MTX, methotrexate; OS, overall survival; PBFCM, peripheral blood flow cytometry; PBL, primary bone lymphoma; PBM-HGBCL, primary bone marrow high-grade B-cell lymphoma; PBR, polatuzumab, bendamustine, rituximab; PET-CT, positron emission tomography-computed tomography; R-CHOP, rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone; R-Hyper-CVAD, rituximab, cyclophosphamide, vincristine, doxorubicin, dexamethasone; R-IPI, revised-international prognostic index; t-PBML, transformed primary bone marrow lymphoma; WBC, white blood cell; WHO, World Health Organization.

Consent for Publication

The study participants or their next of kin have given written informed consent to participate as well as written informed consent to publish the case details and accompanying images. Institutional approval was not required to publish the case details.

Disclosure

The authors report no conflicts of interest in this work.