Consultation with the Specialist: Childhood Leukemia

Abstract

1. Jennifer M. Pearce, MD* 2. Richard H. Sills, MD* 1. *Department of Pediatrics, Albany Medical College, Albany, NY Author Disclosure Drs Pearce and Sills did not disclose any financial relationships relevant to this article. After completing this article, readers should be able to: 1. Understand the similarities in presentation of aplastic anemia and childhood leukemia. 2. Know that the absence of blasts in the peripheral blood of a patient who has pancytopenia does not rule out the diagnosis of leukemia. 3. Recognize bone pain as a symptom of leukemia. 4. Delineate the percentage of patients who have standard-risk acute lymphoblastic leukemia and enter remission with initial treatment. 5. Identify the important sites of relapse of acute lymphoblastic leukemia. 6. Identify the relationship of Down syndrome and leukemia. 7. Recognize the potential for a second malignancy following acute lymphoblastic leukemia. A 3-year-old boy develops pallor, bruising, and intermittent fever over 3 weeks. Laboratory findings include: hemoglobin, 6.8 g/dL (68 g/L); white blood cell (WBC) count, 1.8×10 3 /mcL (1.8×10 9 /L) with 2% neutrophils and 98% lymphocytes; platelet count, 25×10 3 /mcL (25×10 9 /L); mature lymphocytes on blood smear; and normal prothrombin and partial thromboplastin times. He is referred to a pediatric hematologist with the concern of aplastic anemia. The bone marrow is hypercellular and replaced with large blasts; immunophenotyping is consistent with acute myeloid leukemia (AML) (Figs. 1and 2). Figure 1. Photomicrograph of bone marrow aspirate smear from Case 1, showing marrow replaced completely with myeloblasts. Identifying features include the very fine nuclear chromatin, large distinct nucleoli, an irregular nuclear shape, and relatively abundant cytoplasm with red granules. Flow cytometry demonstrates that these cells are myeloid in origin because they are positive for the immunophenotypic markers CD13 and CD33. Figure 2. A. Normal section of bone marrow biopsy with the typical heterogenous appearance due to the presence of the different hematopoietic precursors. The clear areas represent the expected amount of fat. B. Biopsy from Case 1, …