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 B-cell ALL – 85% of all ALL t(12;21) most common in children t(9;22) most common in adults same translocation seen in CML CD10+ and CD19/20+ TdT+ (marker of precursor T- and B-cells) T-cell ALL presents in teenagers CD2-8+ (especially CD3+) TdT+ (marker of precursor T- and B-cells) most common presentation is mediastinal mass infiltration of thymus Epidemiology < 15 years most common type of cancer and leukemia in children most cases with no identifiable risk factor Associated conditions Down syndrome in children > 5 years leukemia in Down syndrome children < 5 years = AML Presentation Symptoms most common symptom is fever acute onset recurrent infections bleeding fatigue Physical exam mediastinal mass from infiltration of thymus hepatosplenomegaly lymphadenopathy Evaluation Best initial test - peripheral blood smear ↑ lymphoblasts Most accurate test bone marrow biopsy with cytogenetics ↑ lymphoblasts (> 25%) TdT+, a marker of pre-T and pre-B cells T-cell ALL CD3+ B-cell ALL CD10+ CD19+ negative MPO (myeloperoxidase) CBC reflects bone marrow crowding by neoplasm anemia thrombocytopenia ↓ mature WBCs Differential Diagnosis AML B-cell lymphoma Non-Hodgkin lymphoma Treatment Chemotherapy Prophylaxis to CNS (standard chemotherapy does not penetrate blood-brain barrier) intrathecal chemotherapy Prognosis, Prevention, and Complications Prognosis very responsive to therapy good prognosis in t(12;21) worse prognosis in t(9;22) Complications likes to spread to CNS and testes DIC tumor lysis syndrome rapid breakdown and turnover of lysed cells causes hyperuricemia hyperkalemia hypocalcemia (most common electrolyte abnormality)
QUESTIONS 1 of 3 1 2 3 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M2.ON.15.4679) A 7-year-old boy is brought to his pediatrician by his mother for recent fatigue and intermittent fevers over the past month. She also reports that her son has appeared much paler recently. Vital signs at today's visit are within normal limits. Physical examination is significant for pallor, petechiae, lymphadenopathy, and hepatosplenomegaly. A complete blood count reveals anemia, thrombocytopenia, and neutropenia. A peripheral blood smear is shown in Figure A. Bone marrow aspiration reveals 47% lymphoblasts. Which of the following is associated with this patient's presenting condition? QID: 107285 FIGURES: A Type & Select Correct Answer 1 Klinefelter syndrome 5% (1/20) 2 Turner syndrome 0% (0/20) 3 Down syndrome 90% (18/20) 4 Edwards syndrome 0% (0/20) 5 Patau syndrome 0% (0/20) M 6 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept