CD20-positive primary gastric T-cell lymphoma poorly responding to initial treatment with rituximab plus CHOP, and a literature review

Abstract

There have been rare reported cases of peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) that co-expressed CD20. A 44-year-old Japanese male was initially misdiagnosed as CD20-positive diffuse large B-cell lymphoma with a background of reactive CD3-positive T-cells in the stomach. After four cycles of R-CHOP [rituximab plus cyclophosphamide (CY), doxorubicin, vincristine, and prednisolone (PSL)], total gastrectomy with regional lymph node dissection was performed due to the poor response to R-CHOP. A final diagnosis of CD20-positive primary gastric PTCL-NOS was made based on the immunohistochemical, flow cytometric, and molecular genetic findings. In the present case, CD20 immunostaining for T-cell lymphoma cells in tumor tissue varied; in a large part, these were strong to weak-positive, and in some parts, absent. We additionally reviewed the literature focusing on CD20-positive PTCL-NOS treated with rituximab. The administration of rituximab has been performed as an initial treatment in 11 cases, including the case reported here. The response was good in cases with high expression of CD20, while it was poor in cases with variable intensity in CD20 staining, which is consistent with our experience in the present case. The efficacy of rituximab may be associated with intensity of CD20 expression in T cells and its homogeneity in the tumor tissue.

Concurrent with T-zone lymphoma and high-grade gastrointestinal cytotoxic T-cell lymphoma in a dog

“…Immunohistochemistry of the small intestine demonstrated that most of the lymphocytes were positive for CD20, CD3 and granzyme B. The CD20-positive primary gastric T-cell lymphoma has been previously reported in humans [8]. The CD20 antigen, a transmembrane protein that functions as a calcium channel, has long been designated a pan-B antigen that is present on a wide range of normal and neoplastic B lymphocytes.…”

“…The CD20 antigen, a transmembrane protein that functions as a calcium channel, has long been designated a pan-B antigen that is present on a wide range of normal and neoplastic B lymphocytes. However, CD20 has been identified in a small subset of normal and neoplastic T lymphocytes using flow cytometry [8]. Although the diagnosis is not well-defined for dogs, we regarded this GI lymphoma as T-cell lymphoma based on the result of positive granzyme B staining, which was expressed exclusively by cytotoxic T lymphocytes.…”

Primary central nervous system extranodal nasal‐type natural killer/T‐cell lymphoma with CD20 expression

“…Kakinoki et al proposed that the efficacy of rituximab for CD20-positive TCL may be associated with intensity of CD20 expression in tumor T-cells and its homogeneity in the tumor tissue. 31 Unfortunately, none of the six cases were treated with rituximab. Further clinical studies are required to determine whether the addition of rituximab offers any survival advantage to these patients with CD20positive ENKTCL.…”

“…However, the efficacy for CD20‐positive T/NK‐cell lymphomas is yet to be known. Kakinoki et al proposed that the efficacy of rituximab for CD20‐positive TCL may be associated with intensity of CD20 expression in tumor T‐cells and its homogeneity in the tumor tissue . Unfortunately, none of the six cases were treated with rituximab.…”

T-cell lymphoma with abundant CD20 expression showing a good response to rituximab with gemcitabine, oxiplatin, and L-asparaginase (R-pGEMOX)

“…Kakinoki et al [ 11 ] reported the successful treatment of 11 patients with CD20-positive T-cell lymphoma with rituximab alone or with rituximab plus chemotherapy. Of these patients, 3 showed strong CD20 staining and 2 showed weak CD20 staining; all were treated with RCHOP.…”