T- Acute lymphoblastic leukemia: Does our understanding of molecular pathogenesis will impact future treatment?

Abstract

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignant neoplasm of the bone marrow. It accounts for 20%of all cases of ALL and is somewhat more common in adults than children, although the incidence diminishes with older age. Its clinical presentation can include hyper-leukocytosis with extra-medullary involvement of lymph nodes and other organs, including frequent central nervous system infiltration and the presence of a mediastinal mass, arising from the thymus. The WHO defines lymphoblasts in TALL as TdT positive with variable expression of CD1a, CD2, CD3, CD4, CD5, CD7, and CD8. Cytoplasmic CD3 and CD7 are often positive. TALL can be subdivided into different stages by intra-thymic differentiation, including pro-T, pre-T, cortical T, and medullary T.