Central nervous system involvement in anaplastic large cell lymphoma in childhood: results from a multicentre European and Japanese study.

In an international study of systemic childhood ALCL, 12/463 patients had CNS involvement, three of which had isolated CNS disease. Comparative analysis of CNS positive and negative patients showed no difference in ALK positivity, immunophenotype, presence of B symptoms or other sites of disease. The lymphohistiocytic variant was over represented in the CNS positive group (36% vs. 5%). With multi-agent chemotherapy, including high dose methotrexate, Ara-C and intrathecal treatment, the event free and overall survival of the CNS positive group at 5 years were 50% (95%CI, 25-75%) and 74% (45-91%), respectively with a median follow up of 4.1 years.