Nodal peripheral T-cell lymphomas and, in particular, their lymphoepithelioid (Lennert?s) variant are often derived from CD8+ cytotoxic T-cells

Abstract

Nodal peripheral T-cell lymphomas are not well understood, and most of them are classified in the "not otherwise specified group" (PTCL-NOS). Data on their normal cellular derivation are ambiguous. Most peripheral T-cell lymphomas are composed of tumor cells and a (sometimes dominant) reactive background, which also includes resting and activated T-lymphocytes. We defined the phenotype of the tumor cells in 101 PTCL-NOS based on their cytological atypia and using immunohistochemical double stains on paraffin sections with CD4/Ki67 and CD8/Ki67. The results were correlated to clinical presentation and outcome. Lineage could be defined in 98 cases (97%). Tumor cells were CD4(+) in 43 cases and CD8(+) in 38. These presented at a younger age but a higher clinical stage compared with the CD4(+) lymphomas. In 15 cases, the atypical cells were CD4(-)CD8(-); two cases were CD4(+)CD8(+). Of 17 lymphoepithelioid (Lennert's) lymphomas, 15 expressed CD8, one each was CD4(+) and CD4(-)CD8(-).

Peripheral T-cell lymphoma, not otherwise specified: a report of 340 cases from the International Peripheral T-cell Lymphoma Project

“…8,10 Asano et al have reported that a cytotoxic phenotype (ie, the expression of TIA-1 or granzyme B) is predictive of poor survival in PTCL-NOS, but EBV was also found in 51% of their cases with a cytotoxic phenotype. 36 We and others 10,37 could not confirm that a cytotoxic phenotype is an adverse prognostic factor in PTCL-NOS. However, Iqbal et al, using gene expression profiling, recently identified a molecular subgroup among PTCL-NOS with features of cytotoxic lymphocytes and a poor survival.…”

“…However, others 38,39 have reported a poor survival for patients with lymphoepithelioid lymphoma. The characteristic morphology and phenotype of lymphoepithelioid lymphoma, which is often derived from CD8 ϩ cytotoxic T cells, 37 as well as the good survival suggest that this special variant of PTCL-NOS should be further studied and possibly separated as a distinctive entity in future lymphoma classifications.…”

Peripheral T-cell lymphoma

“…10 The lymphoepithelioid cell variant appears to be distinct from the others and is usually characterized by CD8 ϩ T cells and a predominance of epithelioid cells in the background. 12 The extranodal group includes a number of less common entities described primarily by their tissue tropism. Hepatosplenic ␥␦ T-cell lymphoma is a disease of children and young adults, 13,14 accounting for 1.4% of PTCL cases.…”

The gene expression profile of nodal peripheral T-cell lymphoma demonstrates a molecular link between angioimmunoblastic T-cell lymphoma (AITL) and follicular helper T (TFH) cells

“…PTCLs-u more commonly express CD4 than CD8, but a significant proportion of the cases have an aberrant phenotype (CD4 ϩ CD8 ϩ or, less commonly, CD4 Ϫ CD8 Ϫ ). [5][6][7] In contrast, it has been suggested that most AITLs derive from mature helper CD4 ϩ CD8 Ϫ T cells, 8 expressing the Th1-associated chemokine receptors CXCR3 and OX40/CD134. 9,10 However, based on the expression of single markers (namely the transcription factor BCL6, 11 the CXCL13 chemokine, [12][13][14] the membrane receptor PD-1 [also known as PDCD1 15 ], and CXCR5 16 ), it has been recently suggested that the neoplastic cells in AITL may derive from a specific subset of T cells normally present in germinal centers with a helper function to follicular B cells (follicular helper T cells, T FH cells).…”