Peripheral T-cell lymphomas. Clinico-pathologic study of 168 cases diagnosed according to the R.E.A.L. classification

Background: One hundred sixty-eight peripheral T-cell lymphomas (PTCLs) were reviewed according to the Revised European-American Lymphoma (R.E.A.L.) Classification. Patients and methods: The cases, originally diagnosed on the basis of the Updated Kiel Classification (UKC), were all provided with histological preparations, immunophenotype, clinical information, and follow- up data. The slides were reclassified by five observers, who integrated the R.E.A.L criteria with cell size measurements. The prognostic value of clinical and pathologic findings was assessed by univariate and multivariate analysis. Results: The R.E.A.L. Classification was reproducibly applied by all of the observers. Clinically, anaplastic large cell lymphomas (ALCLs) differed from the remaining PTCLs by mean age (29.5 vs. 52.9 years), bulky disease (52.3% vs. 11.3%; P = 0.000), mediastinal mass (52.7% vs. 32%; P = 0.004), and disease- free survival (68.0% vs. 38.2%; P = 0.0001). Although each histological type displayed specific clinical aspects. PTCLs other than ALCL were basically characterised by a poor clinical outcome which was not influenced by the UKC malignancy grade. At multivariate analysis, the risk of a lower complete remission rate was related to bulky disease (P = 0.001), histologic group (non- ALCL) (P = 0.01), and advanced stage (III-IV) (P = 0.0002). Conclusions: The present study supports the classification of T-cell lymphomas proposed by the R.E.A.L. scheme.