CD20 Positive T Cell Lymphoma Involvement of Skin

Abstract

CD20 positive T cell lymphoma is a rare condition that is associated with the coexpressions of CD20 and T cell markers, such as, CD3, CD5, or UCHL-1. Positivity for CD20 in this tumor represents an aberrant immunophenotype, but the presence of monoclonal T cell receptor (TCR) gene rearrangements and negativity for immunoglobulin heavy chain gene rearrangement indicate that this tumor is a T cell lymphoma. The majority of cases of CD20 positive T cell lymphoma have been reported as immature peripheral T cell lymphoma not otherwise specified. However, we believe that this disease is likely to be re-listed as a new disease entity after its pathogenesis has been elucidated and more cases have been evaluated. Here, we present a case of peripheral T cell lymphoma coexpressing CD20 and T cell markers with a demonstrable TCR gene rearrangement, in a patient who had been misdiagnosed as having B cell type lymphoma 4 years previously. We hypothesize that in this case initially circulating normal CD20+ T cell subsets underwent neoplastic transformation and CD20 positive T cell lymphoma subsequently developed in the lymph node, and then recurred in the skin due to systemic disease or metastasized from the nodal disease.

EBV-positive diffuse large B-cell lymphoma of the elderly with aberrant expression of CD3 and TIA-1

“…Among the markers to determine B- and T-cell lineages, CD20 and CD3 are the most commonly used. T-cell lymphomas with aberrant expression of the B-cell marker CD20 or B-cell lymphomas with aberrant expression of T-cell associated antigens such as CD5, CD43, CD7, CD2, CD4, and CD8 have been reported [1-5]. However, cases of B-cell lymphoma with CD3 co-expression are extremely rare [6, 7].…”

Pitfalls in the Diagnosis of Cutaneous Lymphoma

“…Of these 11 cases, 6 were PTL-U, 4 were MF, and 1 case was of small/medium CD4+ T-cell lymphoma. 108,114 (Table 4) In addition, Vergier et al 103 in their series of MF cases transformed to large cell lymphoma found CD20-positive reactive B-cells in 18 of 40 cases, many of which also expressed CD20 antigen on transformed large neoplastic T cells as well. Coexpression of CD3 and CD20 was also demonstrated on these large cells in some of these cases (number not specified).…”

“…116 This dual genotype occurs either because of lineage infidelity (a single clone of cells exhibiting both rearrangements) or occurrence of 2 distinct clones in the same lymphoma (first, phenotypically neoplastic cells of particular lineage and second, an oligo or monoclonal clone of reactive cells of other lineage) 116,129 (Table 5). 132 1 PTL-U CD20 Absent Oshima et al 140 1 PTL-U CD20 Absent Balmer et al 141 1 PTL-U CD20 Absent Lee et al 108 1 PTL-U CD20, CD79a Neck lymph node involvement Martin et al 114 1 PTL-U CD20 Absent Martin et al 114 1 MF CD20 Absent Sen et al 115 1 MF CD20 Inguinal lymph node involvement Rahemtullah et al 106 2 MF CD20 Absent Garcia-Herrera et al 25 1 Despite a high prevalence of 50% (2 of 4) 116 and 20% (4 of 13) 130 of dual genotypes in Sezary syndrome found in 2 studies, very few cases of bigenotypic cutaneous lymphomas have been cited in literature. In a large series by Kazakov et al, 129 the dual genotype was seen in only 1% of primary cutaneous lymphomas.…”

“…However, occasional cases of T-cell lymphomas positive for both markers have been documented including 1 case of cutaneous PTL-U. 106,108,109 Rarely, coexpression of other pan B-cell markers, such as T-cell acute lymphoblastic leukemia with CD19 and CD79a positivity, 107 a case of nodal PTL-U with CD20, CD19, and CD79a positivity, 106 and a case of PTL-U involving periscapular soft tissue with CD19 and PAX5 positivity, have been reported. 111 In cutaneous lymphomas, a case of LYP transforming to ALCL has been cited where both initial LYP and transformed ALCL showed positive for PAX5, CD79a, and OCT.2.…”

“…108 Rarely, expression of other pan B-cell markers such as CD79a, CD19, PAX5, and OCT.2 has been demonstrated in T-cell lymphomas. [106][107][108][109][110][111][112][113] The majority of these T-cell lymphomas with aberrant expression are PTL-U. 106,114 Only 11 cases of CTCLs with aberrant expression of CD20 are known in literature.…”