The International Peripheral T-cell Lymphoma Project is a collaborative effort to better understand peripheral T-cell lymphoma (PTCL). A total of 22 institutions submitted clinical and pathologic material on 1314 cases. One objective was toanalyze the clinical and pathologic features of 340 cases of PTCL, not otherwise specified. The median age of the patients was 60 years, and the majority (69%) presented with advanced stage disease. Most patients (87%) presented with nodal disease, but extranodal disease was present in 62%. The 5-year overall survival was 32%, and the 5-year failure-free survival was only 20%. The majority of patients (80%) were treated with combination chemotherapy that included an anthracycline, but there was no survival advantage. The International Prognostic Index (IPI) was predictive of both overall survival and failure-free survival (P < .001). Multivariate analysis of clinical and pathologic prognostic factors, respectively, when controlling for the IPI, identified bulky disease (> 10 cm), thrombocytopenia (< 150 ؋ 10 9 /L), and a high number of transformed tumor cells (> 70%) as adverse predictors of survival, but only the latter was significant in final analysis. Thus, the IPI and a single pathologic feature could be used to stratify patients with PTCL-not otherwise specified for novel and risk-adapted therapies. (Blood. 2011;117(12):3402-3408) IntroductionPeripheral T-cell lymphoma (PTCL) and natural killer/T-cell lymphoma (NKTCL) are an uncommon and heterogeneous group of disorders that compose 5% to 20% of all non-Hodgkin lymphomas (NHLs) in different parts of the world. 1,2 In recent years, the incidence of PTCL and NKTCL in the United States has increased by almost 3-fold with an annual increase of 3.8%, whereas the incidence of B-cell lymphoma and Hodgkin lymphoma has been relatively stable. 3,4 One of the most common subtypes of PTCL is a heterogeneous group of nodal and extranodal mature T-cell lymphomas that do not correspond to any of the specifically defined T-cell entities in the World Health Organization classification, 1 and are therefore called PTCL, not otherwise specified (NOS). Uncommon variants of PTCL-NOS include lymphoepithelioid (Lennert) lymphoma, and cases with a follicular or T-zone pattern of growth. 1 Over the last 12 years, several clinical studies have attempted to identify the clinical and pathologic features of prognostic importance in PTCL-NOS, but the number of cases in these studies was generally small and the findings have been inconsistent or unconfirmed. [5][6][7][8][9][10][11][12][13] The International Peripheral T-cell Lymphoma Project was undertaken as a large retrospective study of PTCL and NKTCL in North America, Europe, and Asia with the goal of better characterizing this group of NHL. One objective of was to analyze the clinical and pathologic features of the 340 cases of PTCL-NOS in the study, and to determine the important prognostic factors for this uncommon entity. MethodsTwenty-two institutions in North America, Europe, and Asia partici...

Nodal MZL seems to be a distinctive disease entity rather than an advanced stage of MALT-type MZL because the clinical presentations and survival outcomes are different in these two types of MZL. Clinically, nodal MZL is similar to other low-grade, node-based B-cell lymphomas, such as follicular and small lymphocytic lymphomas.