How I treat newly diagnosed and refractory T-cell acute lymphoblastic lymphoma in children and young adults.

T-cell lymphoblastic lymphoma (T-LLy) and T-cell acute lymphoblastic leukemia (T-ALL) have historically been considered a spectrum of the same disease. However, recent evidence demonstrating differential responses to chemotherapy raise the possibility that T-LLy and T-ALL are distinct clinical and biologic entities. Here, we examine differences between the 2 diseases and use illustrative cases to highlight key recommendations on how to best treat patients with newly diagnosed and relapsed/refractory T-LLy. We discuss results of recent clinical trials incorporating use of nelarabine and bortezomib, choice of induction steroid, role of cranial radiotherapy, and risk stratification markers to identify patients at highest risk of relapse and to further refine current treatment strategies. Because prognosis for relapsed or refractory T-LLy patients is poor, we discuss ongoing investigations incorporating novel therapies, including immunotherapeutics, into upfront and salvage regimens and the role of hematopoietic stem cell transplantation.