PERIPHERAL T-CELL LYMPHOMA - A CLINICOPATHOLOGICAL STUDY OF 41 CASES AND EVALUATION OF THE PROGNOSTIC-SIGNIFICANCE OF THE UPDATED KIEL CLASSIFICATION

A total of 41 non-cutaneous peripheral T-cell lymphomas were classified following the updated Kiel classification. Of these, 20 cases belonged to the low-grade group (T-cell chronic lymphocytic leukaemia, 3: lymphoepithelioid, 5; angioimmunoblastic, 4; pleomorphic small cell, 8) and 21 to the high grade group (pleomorphic medium and large cell, 11; immunoblastic, 3, large-cell anaplastic Ki-1 positive, 7). Seventy per cent showed a CD4 + /CD8-phenotype, 39% a defective phenotype and 88% an activation phenotype. Eighty per cent had B-symptoms, 63% hepatomegaly, 48% splenomegaly and 26% had involvement of more than three lymphoid areas. Bone marrow was infiltrated in 34%, central nervous system in 4%, lung in 12% and skin in 14.6%. Seventeen per cent presented with extranodal disease and 82.8% had stage III/IV disease. Hypergammaglobulinaemia was found in 29%, hypercalcaemia in 7%, raised LDH serum levels in 58% and HTLV-1 antibodies in only one case. Of the 37 treated patients 18 (48%) achieved a complete remission, but 33% relapsed. Mortality was 59% and actuarial overall survival at 38 months was 0.32. In the comparison of the clinical, analytical and immunophenotypic variables and outcome between low and high grade groups, only the average of bone marrow infiltration in the low grade and stage I-II, presence of defective phenotypes and higher Ki-67 positivity in the high grade group were significantly different. In the statistical studies, extranodal presentation and the failure to achieve a complete remission were the only variables that influenced mortality: there were no significant differences in the general features of the low and high grade groups and only minor differences were found in the immunoblastic and angioimmunoblastic subgroups. There were no differences in the actuarial survival between the low and high grade groups, among the subgroups of the Kiel classification, among stages I to IV, between patients with or without B-symptoms, with or without defective phenotypes, Ki-67 positivity over or under 60%, or among different CD4/CD8 phenotypes. The updated Kiel classification did not separate groups with a prognostic significance.