T-Acute Lymphoblastic Leukemia

Abstract

Abstract Acute lymphoblastic leukemia (ALL) is a condition in which immature white blood cells (WBCs) accumulate in the bone marrow, resulting in the crowding of normal WBCs and buildup in the liver, spleen, and lymph nodes. ALL is a malignancy of B or T lymphoblasts. B lymphocytes protect the body against bacteria and viruses through production of antibodies, which can directly destroy target cells or trigger others to do so. T lymphocytes directly destroy bacteria or cells infected with viruses. Approximately 20% of all ALL patients are categorized specifically to suffer from T-cell ALL (T-ALL), and it is seen to be more prevalent in the adult population in comparison with children, with incidences shown to diminish with age. Among T-ALL cases in the pediatric population, a median onset of age 9 has been identified and the disease is particularly prominent among adolescents. The disease stems from cytogenic and molecular abnormalities, resulting in disruption of developmental pathways controlling thymocyte development, tumor suppressor development, and alterations in control of cell growth and proliferation. Distinct from adult T-cell leukemia where T-cell lymphotropic virus type I causes malignant maturation of T cells, T-ALL is a precursor for lymphoid neoplasm. Its clinical presentation most commonly includes infiltration of the central nervous system and further identifies mediastinal mass presence originating from the thymus, along with extramedullary involvement of multiple organs including the lymph node as a result of hyperleukocytosis.