Lymphoblastic lymphoma: an updated review on biology, diagnosis, and treatment.

Lymphoblastic lymphoma is a rare aggressive neoplasm of T-/B-precursors resembling acute lymphoblastic leukemia, with no or limited bone marrow involvement (<25%), that develops more frequently in children and young adults and is typically characterized by a grossly enlarged mediastinum, and whose diagnostic hallmark is the expression of a T-/B-precursor cell immunophenotype, the T-cell subset accounting for 90% of all cases. The adoption of pediatric-derived, intensive lymphoblastic leukemia-like protocols led to significantly improved results, with survival rates of about 70% and 90% in adults and children, respectively. Adequate central nervous system prophylaxis and mediastinal irradiation contributed to the therapeutic success; however, the role of radiation therapy is debated due to toxicity concerns and the excellent results obtained with radiation-free programs especially in pediatric patients. With these modern schedules, localized radiotherapy and/or hematopoietic stem cell transplants could be generally omitted, and considered only for high-risk patients identified through postinduction computed tomography/positron-emission tomography scans, minimal residual disease analysis, and new genetics and genomics. New clinical studies will have to confirm the value of these assays for risk-oriented therapy, while further therapeutic progress is expected from the introduction of new drugs and targeting agents.