Anaplastic lymphoma kinase (ALK) positive anaplastic large cell lymphoma (ALCL) is usually associated with a favorable prognosis. We describe an 11-year-old girl patient with ALK positive ALCL bearing t(2;5)(p23;q35) and t(8;17)(q24;q25) translocations who had an aggressive clinical course despite various combinations of intensive chemotherapy. Southern blot analysis identified C-MYC rearrangement. Immunohistochemistry and Northern and Western blot analyses revealed cmyc overexpression. A new fusion between ALO17 (ALK lymphoma oligomerization partner on chromosome 17) and C-MYC was identified by the 50-rapid amplification of cDNA ends. This new fusion may have possibly provoked the poor prognosis in this patient with ALK positive ALCL, and C-MYC rearrangement may indicate poor prognosis in ALCL.