Acute Lymphoblastic Leukemia (ALL) is the most common cancer in children, but it can also occur in adults of all ages. There is a bimodal distribution, with peaks at 3-7 years and 65 years of age. The clinical presentation of ALL is nonspecific: fever, infection, bleeding, bone pain, lymphadenopathy, and CNS involvement. The classification of ALL is based on the evaluation of cells derived from a bone marrow aspirate or tissue biopsy specimens. Clonal cells may be B cells (B-precursor lineage, 75%) or T cells. Management involves remission induction with combination chemotherapy. In addition, intrathecal chemotherapy is indicated for all patients to prevent CNS relapse. Once remission is achieved, patients undergo 1-3 years of maintenance therapy to eliminate residual disease. Source