The diagnosis and prognosis of T-lymphoblastic lymphoma/leukemia represent a clinical challenge due to their relative rarity as well as their heterogeneous morphology and immunophenotype. In contrast to the significant progress in uncovering genetic lesions and prognostic factors for B-cell lineage lymphoid malignancies, prognostic markers that can predict clinical outcome of T-lymphoblastic lymphoma/leukemia remain to be discovered and validated. Recently, specific micro-RNAs have emerged as potential biomarkers for the diagnosis and prognosis of various types of tumor. Among them, miR-16 is known to play important roles in the development of hematological malignancies. Using quantitative real-time reverse transcription polymerase chain reaction, we analyzed miR-16 expression level in archived formalin-fixed and paraffin-embedded diagnostic lymph node specimens from a total of 72 patients with T-lymphoblastic lymphoma/leukemia and for which clinical follow-up information was available. Although no statistically significant difference was evident in patients with T-lymphoblastic lymphoma/leukemia Versus controls with reactive lymph nodes (P = .163), T-lymphoblastic lymphoma/leukemia patients with a greater than median expression level of miR-16 had a longer overall survival than patients with a less than median expression level. The overall 1-year survival rate was 50% for the high expression group but was 26.5% for the low expression group (P = .043). To our knowledge, we provide here the first evidence that the expression of a single micro-RNA, miR-16, is associated with clinical outcome of patients with T-lymphoblastic lymphoma/leukemia. Therefore, miR-16 may be considered as a potential prognostic marker for T-lymphoblastic lymphoma/leukemia. (C) 2013 Elsevier Inc. All rights reserved.