An unusual case report of indolent T-cell lymphoproliferative disorder with aberrant CD20 expression involving the gastrointestinal tract and bone marrow

Abstract

BackgroundIndolent T-cell proliferative disorder of the GIT is a rare and provisional entity in the revised WHO 2016 classification. The patients usually have prolonged survival with persistent disease even without any treatment.Case presentationThe 46 years old male patient has been followed up for more than 6 years without chemotherapy. Repeated gastrointestinal biopsies showed expansion of the lamina propria extending to the submucosa by small to medium sized lymphocytes with minimal cytologic atypia. The lymphoid cells were positive for CD3, CD43, TIA-1, CD2, CD7 and the B-cell marker CD20; but negative for CD4, CD8, PAX5, CD56, cyclinD1, granzyme (GraB) and Epstein Barr virus-encoded RNA (EBER). Ki-67(MIB1) index was less than 10%. Molecular tests demonstrated a clonal rearrangement for T-cell receptor γ (TCR γ) gene but immunoglobulin chain (IgH, IgK, IgL) gene remained germline. Recognition of possible aberrant CD20 expression in indolent T-cell LPD is important to avoid potential diagnostic pitfall and improper treatment.ConclusionsWe present an unusual case of indolent T-cell lymphoproliferative disorder with aberrant CD20 expression, Recognition of this unusual immunophenotype of indolent T-cell LPD of GI helps to eschew misdiagnosis of B-cell and other high grade lymphomas and inappropriate aggressive treatment.

Indolent T cell lymphoproliferative disorder of the gastrointestinal tract: an uncommon case with lymph node involvement and the classic Hodgkin’s lymphoma

“…using analysis of cellular morphology, immunostaining, as well as genetic analysis. Our findings support the conclusion that that indolent, pathologic cells can distantly infiltrate other tissues, which is in agreement with a prior report on ITCLD-GT (21). ITCLD-GT usually are Epstein-Barr virus (EBV) negative (22), most cases of HL are EBV negative too.…”

“…This is because chemotherapy is not recommended, as most patients have a good prognosis even without drug therapy (5-7). Prior reports suggest pathological cells usually remain in the GIT and are not likely to infiltrate distant sites (21). Lesion progression into a higher grade lymphoma has been reported but this conclusion remains controversial (14,22).…”

Oral manifestation of indolent T‐cell lymphoproliferative disorder of the gastrointestinal tract: A potential diagnostic pitfall

“…Most reported patients (65%) exhibited a CD4(+) CD8(−) phenotype, with the remainder being composed of CD4(−) CD8(+) cytotoxic cases (as in our patient), as well as rare double negative CD4(−) CD8(−) and double‐positive CD4(+) CD8(+) cases . Expression of B‐cell markers (as CD20 in our case) is very infrequent but not unprecedented; a similar phenomenon has been already described in other indolent NHLs, including MF, and should be considered as an aberrant immunophenotype with little biological or prognostic relevance. The Ki‐67 proliferation index is normally very low (<10%), CD30 is not expressed (with exception of rare cases undergoing large‐cell transformation), and in situ hybridization for EBV infection yields a negative result .…”

Indolent T-cell lymphoproliferative disorder of the gastrointestinal tract: a tricky diagnosis of a gastric case

“…Dissemination to other organs can be observed with disease progression [1,4]. Bone marrow involvement has been infrequently reported [5,9,10]. Higher-grade T-cell lymphomas may rarely develop in a subset of cases [1].…”