Regular Article CLINICAL TRIALS AND OBSERVATIONS Central nervous system relapse in peripheral T-cell lymphomas: a Swedish Lymphoma Registry study

• CNS involvement at relapse/ progression in PTCL occurred at a frequency similar to what is seen in aggressive B-cell lymphomas. • Outcome after relapse is generally very poor in patients with PTCL and is not significantly altered by presence of CNS involvement at relapse. Central nervous system (CNS) relapse in non-Hodgkin lymphoma (NHL) carries a very poor prognosis. Risk factors and outcome have been studied in aggressive B-cell lym-phomas, but very little is known about the risk in peripheral T-cell lymphoma (PTCL). We aimed at analyzing risk factors for CNS involvement at first relapse or progression, as well as the outcome of these patients, in a large population-based cohort of patients with PTCL. Twenty-eight out of 625 patients (4.5%) developed CNS disease over time. In multi-variable analysis, disease characteristics at diagnosis independently associated with an increased risk for later CNS involvement were involvement of more than 1 extranodal sit