Peripheral T-cell lymphomas: a clinicopathologic study of 75 cases.

Seventy-five peripheral T-cell lymphomas (PTLs) were classified according to the recently proposed "Updated Kiel Classification of Non-Hodgkin's Lymphomas" (mycosis fungoides and Sezary's syndrome excluded). Thirty-seven PTLs belonged to the low-grade category (T-cell chronic lymphocytic leukemia [T-CLL], 3; lymphoepithelioid, 4; angioimmunoblastic, 22; T-zone, 6; pleomorphic small cell, 2) and 38 belonged to the high-grade category (pleomorphic medium and large cell, 24; immunoblastic, 1; large-cell anaplastic Ki-1-positive, 13). Loss of pan-T antigens occurred exclusively in high-grade PTLs; on paraffin sections UCHL 1 was slightly more sensitive than MT 1. Sixty patients presented with lymphadenopathy and 15 patients (20%) presented with extranodal disease most frequently affecting the skin and upper aerodigestive tract. B-cell lymphoma symptoms were found in 43 cases (57%) and bone marrow involvement (T-CLL excluded) was found in 12 cases (17%). Staging (T-CLL excluded) revealed stage I in 13%, stage II in 15%, and stages III and IV in 72% of the cases. Among the intensively treated patients, 37% achieved complete remission and 15 are still in complete remission after 4 to 79 months (median: 24 months). The overall median survival (MS) rate was 23 months. Peripheral T-cell lymphoma of pleomorphic medium and large-cell type was the most aggressive lymphoma (MS: 8 months). B-cell lymphoma symptoms, bone marrow involvement, and Ki-67 positivity 60% or greater significantly shortened survival times, whereas age (under 60 versus over 60 years), stage (I and II versus III and IV), and grade had no significant influence. Ki-67 reactivity was found to be a prognostic factor which allows prediction of probable poor outcome, especially in cases with limited stage of disease.