Snapshot A 7-year-old boy presents with low-grade fever and fatigue. He is notably pale. On physical exam, he has bilateral cervical lymphadenopathy and a mediastinal mass. Blood smear shows increased lymphoblasts. He is referred for a bone marrow biopsy. Introduction Acute leukemia of lymphoid precursor cells that occurs in children Subtypes login to view 12 more bullets Epidemiology < 15 years Most common type of cancer and leukemia in children Most cases with no identifiable risk factor etiology Associated conditions login to view 2 more bullets Presentation Symptoms login to view 5 more bullets Physical exam login to view 3 more bullets Evaluation Best initial test - peripheral blood smear login to view 1 more bullet Most accurate test login to view 9 more bullets CBC reflects bone marrow crowding by neoplasm login to view 3 more bullets Differential Diagnosis AML B-cell lymphoma Non-Hodgkin lymphoma Treatment Chemotherapy Prophylaxis to CNS (standard chemotherapy does not penetrate blood-brain barrier) login to view 1 more bullet Complications Likes to spread to CNS and testes DIC Tumor lysis syndrome login to view 4 more bullets Prognosis Very responsive to therapy Good prognosis in t(12;21) Worse prognosis in t(9;22)