Relationship between atypical T- and B-cell size predicts survival in peripheral T-cell lymphomas with large B-cells

Pathological prognostication for peripheral T-cell lymphomas (PTCLs) complicated by large B-cell (LBC) proliferations has not been previously devised.

Forty-six cases of PTCL with LBCs were reviewed immunohistologically, by in situ hybridisation for Epstein-Barr virus encoded RNA and polymerase chain reaction analyses for T-cell receptor (TCR) clonality. Follow-up intervals ranged from 1 to 149 months (mean 40 months).

Cases with atypical T-cell size equal to or exceeding that of interspersed LBCs (ATEB+, n = 12, including an ALK negative anaplastic large cell lymphoma) had significantly inferior disease-specific survival compared to ATEB negative (ATEB-, n = 34) cases (p = 0.002 for all cases and p = 0.014 when restricted to TCR clonal cases, n = 30) [hazard ratio 11.2; 95% confidence interval (CI) 0.94-85.0, p = 0.019]. All recorded deaths amongst ATEB+ cases occurred in 26 months, while TCR polyclonal ATEB- cases (n = 9) had none; TCR clonal ATEB- cases (n = 22) had 62% 5-year survival (95% CI 33-91%, p = 0.001). There was no survival separation between angioimmunoblastic (n = 25) and unspecified (n = 20) subsets of PTCL (p = 0.957).

In PTCLs, cytological grading using harboured LBCs as internal yardsticks, as well as molecular genotypic measures of lymphoma cell burden, have prognostic value.