Nodal cytotoxic molecule (CM)‐positive Epstein–Barr virus (EBV)‐associated peripheral T cell lymphoma (PTCL): a clinicopathological study of 26 cases

Abstract

The clinicopathological distinctiveness of nodal cytotoxic molecule (CM)-positive Epstein-Barr virus (EBV)-associated peripheral T cell lymphoma (PTCL) remains to be clarified. We investigated 26 patients with this lymphoma compared to nodal CM(+) EBV(-) PTCL (n = 39) and extranasal natural killer/T cell lymphoma of nasal type (ENKTL, n = 44). Nodal CM(+) EBV(+) PTCL patients were more likely to have B symptoms (P = 0.019) and hepatic involvement (P = 0.026) than nodal CM(+) EBV(-) PTCL patients. The former also had more Stage III/IV disease (P = 0.025) but much less cutaneous involvement (P < 0.001) than ENKTL patients at diagnosis. This nodal EBV(+) lymphoma possessed a distinctive immunophenotype of high CD8(+), CD56(-) pattern with an aggressive clinical course (median, 6.6 months). Thrombocytopenia was present in 11 (50%) patients and found to be the strongest prognostic indicator (P = 0.001) in this nodal EBV(+) group. For all nodal CM(+) PTCL cases CD5 negativity, but not EBV positivity, was the significant adverse prognostic factor (P < 0.002) in a multivariate analysis, independent of prognostic index for PTCL (PIT) or International Prognostic Index (IPI) scores. Nodal CM(+) EBV(+) PTCL constitutes a unique group of lymphomas distinct from ENKTL. The data provide support for our assertion that nodal CM(+) PTCL should be distinguished in the 2008 WHO category of PTCL, not otherwise specified.