[Peripheral T-cell lymphoma: diagnosis and treatment]

Peripheral T/NK-cell lymphomas (PTCL) comprise a heterogeneous group of rare diseases accounting for approximately 10-15% of all non-Hodgkin"s lymphomas. Compared to B-cell lymphomas, PTCL more frequently involve extranodal sites and have a worse prognosis. Because of their usually indolent course, primary cutaneous T/NK-cell lymphomas should be distinguished from the other PTCL. Staging of PTCL is done according to the Ann Arbor staging system. The International Prognostic Index, established for aggressive B-cell lymphomas, has also proved relevant for PTCL. Standard therapy for PTCL has not been defined, yet. First line anthracycline-based chemotherapy brings about long-term remissions in 15 to 42% of patients. Apart from (ALK-positive) anaplastic large cell lymphoma it thus gives poorer results than those obtained in patients with aggressive B-cell lymphomas. Data for high-dosage therapy with autologous stem cell transplantation (autoSCT) for relapsing and refractory PTCL are similar to those reported for aggressive B-cell lymphomas. Thus this treatment seems to constitute a sensible salvage strategy. Allogeneic stem cell transplantation following reduced conditioning regimens has also given promising results in patients with relapse. However, the impact of high-dosage strategies and the implementation of newer agents, such as alemtuzumab, in first-line treatment are still uncertain. Hence patients with PTCL should be treated within clinical trials.