Rituximab Plus Chemotherapy Provides No Clinical Benefit in a Peripheral T-Cell Lymphoma not Otherwise Specified with Aberrant Expression of CD20 and CD79a: A Case Report and Review of the Literature

Abstract

Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is the most common entity of mature T-cell neoplasms. PTCL-NOS generally has an aggressive behavior and is often refractory to standard therapy. Only a few cases of PTCL with aberrant expression of B-cell antigens have been reported so far. This phenotypic aberrancy may lead to misdiagnosis as B-cell non-Hodgkin lymphomas and eventual inappropriate patient management, whereas in an accurately diagnosed PTCL, the presence of CD20 may appear as an appealing therapeutic target. In this setting, response to anti-CD20 monoclonal antibody in combination with chemotherapy has been poorly explored. We describe the case of a 59-year-old male diagnosed by a pathological and molecular approach as PTCL-NOS with aberrant co-expression of the B-cell antigens CD20 and CD79a, which proved non-responsive to the addition of rituximab to standard polychemotherapy. This case highlights that the presence of CD20 in PTCL may be misleading in the diagnosis and also act as a lure for the clinician to adopt a rituximab-based treatment, the effectiveness of which is undefined as the molecular mechanisms underlying B-cell marker expression in PTCL.

Development of an immune-related prognostic index associated with osteosarcoma

“…In the univariate survival analysis, the expression of nine IRGs was found to be markedly related to the TARGET database prognosis. The PI model was then constructed by multivariate Cox CD79a is part of the B cell receptor, and most T cell neoplasms do not express CD79a proteins [20]. High immune infiltration of CD79a+ B cells in the tumor stroma tends to be associated with good survival in colorectal liver metastasis patients [21].…”

“…CD79a is part of the B cell receptor, and most T cell neoplasms do not express CD79a proteins [ 20 ]. High immune infiltration of CD79a+ B cells in the tumor stroma tends to be associated with good survival in colorectal liver metastasis patients [ 21 ].…”

Constitutive PSGL-1 Correlates with CD30 and TCR Pathways and Represents a Potential Target for Immunotherapy in Anaplastic Large T-Cell Lymphoma

“…In particular, we focused our interest on peripheral T-cell lymphomas (PTCLs), a heterogeneous group of aggressive non-Hodgkin lymphomas (NHLs), distinguishing among the most common subtypes of PTCLs: PT-CLs, not otherwise specified (PTCLs, NOS), anaplastic large-cell lymphomas (ALCLs) and angioimmunoblastic T-cell lymphomas (AITLs) [26,27]. No effective targeted therapies have been yet identified for PTCLs, except for Brentuximab vedotin, an antibody-drug conjugated for targeting the TNF-receptor CD30 [28], and Rituximab, currently used for the treatment of CD20-positive PTCLs [29,30].…”

A Patient With CD20-positive T-cell Lymphoma Concurrently Exhibiting B-cell Neoplasm-related Genetic Abnormalities Shows Clonal Escape Post CD20-targeting Treatment

“…Most reported B-cell antigen-expressing T-cell lymphomas are CD20-expressing PTCL, NOS [1][2][3][4][5][6][7][8][9]; only three patients with this disease showed BM involvement. However, CD19 or CD79a can also be expressed [1][2][3], which can complicate the diagnosis given that CD20, CD19, and CD79a are considered to have near-absolute lineage specificity in mature lymphoid neoplasms.…”

“…Most reported B-cell antigen-expressing T-cell lymphomas are CD20-expressing PTCL, NOS [1][2][3][4][5][6][7][8][9]; only three patients with this disease showed BM involvement. However, CD19 or CD79a can also be expressed [1][2][3], which can complicate the diagnosis given that CD20, CD19, and CD79a are considered to have near-absolute lineage specificity in mature lymphoid neoplasms. It is also important to distinguish T-cell lymphoma with CD20 expression from that admixed with non-malignant B-cells, which can be accomplished by confirming the co-expression of CD20 and other T-cell antigens, including CD2, CD5, CD7, and particularly, CD3 via flow cytometry or dual-stain immunohistochemistry.…”