CD20-negative diffuse large B-cell lymphoma presenting with lactic acidosis

Primary Nodal Unclassifiable CD20 Negative Diffuse Large B-cell Lymphoma With Dual IgK and TCR Gene Rearrangement: A Diagnostic Challenge

Non-Hodgkin lymphomas are most frequently classified based on the lineage marker expression. However, lymphomas with aberrant marker expression as well as monoclonal IgH/IgΚ and TCR gene rearrangements may co-exist which can be misleading and confusing. Primary CD20 negative diffuse large B-cell lymphomas (DLBCL) represent a rare entity, and they account for 1% to 3% of cases. However, some CD20 negative DLBCLs could not be classified into known variants, creating both diagnostic and therapeutic dilemma's. Primary CD20 negative DLBCL are more likely to have a non-germinal centre subtype, a higher proliferation index, more frequent extra-nodal involvement, a poorer response, and poorer prognosis to conventional treatment compared to CD20 positive DLBCL. A 66- year-old postmenopausal lady, presented with palpable, bilateral neck lymphadenopathy and difficulty swallowing. She also had left leg lymphoedema, poor appetited, fatigue and weight loss. Her symptoms lasted approximately 1 month. After histological, immunohistochemical and clonality analysis of the lymph node the patient was diagnosed with primary nodal CD20 and PAX-5 negative DLBCL with dual immunoglobulin light-chain kappa (IgK) and T-cell receptor (TCR) gene rearrangement. This unusual and unique case presented a diagnostic challenge because it was CD20 and PAX-5 negative, had dual IgK and TCR gene rearrangement and, it could not be classified within the known and well established CD20 negative DLBCL variants. Describing such cases emphasises the fact that lymphomas unclassifiable within known variants of CD20 negative DLBCL do exist and that range and heterogeneity of CD20 negative DLBCL continues to evolve, and pathologist should be aware of these uncommon, atypical mature B-cell neoplasms.

Primary central nervous system CD20-negative diffuse large B-cell lymphoma: a case report

BACKGROUND

CD20-negative diffuse large B-cell lymphoma is a very rare and heterogeneous invasive cancer characterized by chemical resistance and poor prognosis. Primary CD20-negative diffuse large B-cell lymphoma of the central nervous system is even rarer, presenting great challenges in pathological diagnosis and clinical treatment.

CASE PRESENTATION

We report a case of primary CD20-negative diffuse large B-cell lymphoma of the CNS in a 54-year-old woman admitted to the hospital with a headache lasting more than 10 days. CT and MRI scans showed right temporal lobe lymphoma. Microscopically, large infiltrating lymphoid cells that induced brain tissue damage were observed. Immunohistochemistry showed that the tumor cells were CD79a⁺, PAX-5⁺, MUM1⁺, and CD20^-. The patient was diagnosed with lymphoma and transferred to an oncology hospital for chemotherapy. However, because the disease progressed rapidly, the patient died only after two rounds of chemotherapy.

CONCLUSIONS

To the best of our knowledge, this is one of the first reported cases of unclassifiable CD20-negative diffuse large B-cell lymphoma located in the CNS. This case report aims to deepen the understanding of clinicopathological features of this type of lymphoma and expand the scope of this disease.

Case report of primary CD20 negative diffuse large B-cell lymphoma

Few groups of aggressive non-Hodgkin's lymphomas (NHL) that are refractory to standard chemotherapy are rarely reported. Primary CD20 negative diffuse large B cell lymphoma (DLBCL) without human immunodeficiency virus infection is an uncommon presentation and this case report is challenging in terms of diagnosis and treatment as well.

A Clinical Triad with Fatal Implications: Recrudescent Diffuse Large B-cell Non-Hodgkin Lymphoma Presenting in the Leukemic Phase with an Elevated Serum Lactic Acid Level and Dysregulation of the TP53 Tumor Suppressor Gene - A Case Report and Literature Review

Despite representing 30% to 40% of newly diagnosed cases of adult non-Hodgkin lymphoma, diffuse large B-cell lymphoma (DLBCL) rarely presents (1) in the leukemic phase (2) with dysregulation of the TP53 tumor suppressor gene and (3) an elevated serum lactic acid level. In this case report and literature review, we highlight this unfortunate triad of poor prognostic features associated with an aggressive and fatal clinical course in a 53-year-old man with recrudescent DLBCL. A leukemic presentation of de novo or relapsed DLBCL is rare and may be related to differential expressions of adhesion molecules on cell surfaces. In addition, TP53 gene mutations are present in approximately 20% to 25% of DLBCL cases and foreshadow worse clinical outcomes. Finally, an elevated serum lactic acid level in DLBCL that is not clearly associated with sepsis syndrome is a poor prognostic factor for survival and manifests as type B lactic acidosis through the Warburg effect.

Severe Type B Lactic Acidosis in a Rare and Aggressive HIV-Related Lymphoma

We describe the prognostic implication and aggressive clinical course of lymphoma-related lactic acidosis in a rare HIV-related lymphoma. Patient was diagnosed with plasmablastic lymphoma and developed severe lactic acidosis, and was treated on the medical floor and in the medical intensive care unit. Her lactic acidosis was considered to be type B, secondary to her underlying lymphoma since she never had an infectious source, hypovolemic state, or low/high cardiac-output state. The mechanism of the lymphoma-related lactic acidosis is from altered cellular metabolism, thought to aid in lymphoma proliferation, rather than tissue hypoperfusion. It is a rare complication of aggressive lymphomas and signifies a poor prognosis. Patients having this complication should be considered for close monitoring and management in an intensive care unit until definitive treatment (i.e., chemotherapy) can be implemented.

CD-20 Negative Plasmablastic Lymphoma Lurking in the Shadow of a Leiomyoma - Diagnosis and Management

CD20-negative diffuse large B-cell lymphoma (DLBCL) is a rare entity and constitutes 1-2% of all DLBCLs. Major subtypes include plasmablastic lymphomas (PBLs), primary effusion lymphomas, anaplastic kinase positive large B-cell lymphomas, and large B-cell lymphomas arising in human herpesvirus 8 (HHV8)-associated multicentric Castleman disease. Amongst the known subtypes, PBL is the most common and presents as an aggressive extranodal disease with high resistance to routine chemotherapy regimens, thereby posing a therapeutic challenge. Though more commonly seen in HIV-positive patients, PBL cases have also been reported in HIV negative patients. We report a unique case of PBL with pelvic organ involvement in an HIV/Epstein-Barr virus-negative patient. The neoplastic cells were found to be positive for CD79a, MUM1, BCL6, and PAX5, with a Ki-67 proliferation index of 92%. Our case met the criteria for the plasmablastic variant, and remission was obtained with etoposide, vincristine, and doxorubicin with bolus doses of cyclophosphamide and oral prednisone (EPOCH) therapy. This case report aims to highlight the challenges related to the diagnosis and treatment of CD20-negative DLBCL, with special emphasis on the PBL subtype and to provide an insight into some of the upcoming, less conventional treatment modalities.

De Novo Unclassifiable CD20-Negative Diffuse Large B-Cell Lymphoma: A Diagnostic and Therapeutic Challenge

CD20-negative diffuse large B-cell lymphomas (DLBCLs) constitute a rare and heterogeneous group of aggressive lymphomas. Known well-documented variants include plasmablastic lymphomas, primary effusion lymphomas, anaplastic kinase-positive large B-cell lymphomas, and large B-cell lymphomas arising in human herpesvirus 8 (HHV8)-associated multicentric Castleman disease. They impose diagnostic challenges for pathologists and therapeutic confrontations for clinicians. CD20 loss in B-cell lymphomas is a well-known phenomenon after rituximab therapy. De novo loss of CD20 has been reported in human immunodeficiency virus (HIV)-positive patients. Rare cases of primary CD20-negative DLBCLs that did not meet the criteria of the well-established subtypes of CD20-negative DLBCLs have been reported. This might expand the spectrum of unclassifiable CD20-negative DLBCLs with aberrant genetic and immunophenotypes. This imposes further diagnostic and therapeutic challenges. We report a case of a primary CD20-negative DLBCL in an HIV-infected female patient with an Epstein Barr virus (EBV) coinfection, who presented with generalized lymphadenopathy and fever. The nodal neoplastic immunoblasts were positive for LCA, PAX5, CD30, OCT2, BOB1, MUM1, CD79a, and CD19. Ki67 proliferation index was 100%. They were negative for CD20, CD3, ALK, EMA, CD138, CD38, EBV, and HHV8. Our case did not meet the criteria of the known variants of CD20-negative DLBCLs. The aim of this study is to highlight the diagnostic challenges associated with CD20-negative DLBCLs. De novo unclassifiable CD20-negative DLBCLs might raise an insight into the complex genetic mechanisms of CD20 concealment with variable immunoprofiles and resistance to conventional chemotherapies.

Diagnosis and treatment of CD20 negative B cell lymphomas

CD20 negative B cell non-Hodgkin lymphoma (NHL) is rare and accounts for approximately 1-2% of B cell lymphomas. CD20- negative NHL is frequently associated with extranodal involvement, atypical morphology, aggressive clinical behaviour, resistance to standard chemotherapy and poor prognosis. The most common types of these include plasmablastic lymphoma, primary effusion lymphoma, large B-cell lymphoma arising from HHV8-associated multicentric Castleman’s disease, and ALK+ large B cell lymphoma. This review provides an overview of the diagnostic and treatment modalities for CD20 negative B cell NHL.