Leukemia

• Most common pediatric malignancy
• 1/3 of all malignancies in children
• Often have severe bone pain out of proportion to physical exam
• Types: ALL 75%, AML 20%, CML 5%
• Annual incidence: 43.7 per million in Caucasians, 24.3 per million in African-Americans
• Down Syndrome 15-20x increased incidence of acute leukemia
• CHLA Rule out leukemia protocol

Acute Lymphoblastic Leukemia (ALL)
Features of ALL relapse
Acute Myeloid Leukemia
Chronic Myeloid Leukemia
Chloroma
Tumor Lysis Syndrome
Varicella Exposure and Chemo

Leukemic lines

1. What is the most common pediatric malignancy?
2. What other diseases/syndromes have increased risk of ALL?
3. What are leukemic lines?
4. What is standard risk ALL?
5. there are the common sites of relapse for ALL?
6. What diseases/syndromes predispose a patient for AML?
7. What is a chloroma? Where are they commonly located? What is it seen in?

Answers

1. Leukemia!
2. Wiscott-Aldritch, Ataxia-telangiectasia, Down, congenital hypogammaglobulinemia
3. Lucent lines at the metaphyses of long bones
4. Age 1-10yo, WBC<50K, no mediastinal mass, no CNS involvement, B phenotype
5. BM, CNS, testes
6. Down, Diamond-Blackfan, Fanconi’s anemia, Bloom’s, Kostmann’s, NF
7. Localized mass of leukemic cells; Orbital or epidural areas; AML

General Discussion

Leukemia, the most common childhood cancer, affects about one of every 2,500 children under 15 years old in the United States each year. It can be classified as acute or chronic, based on the maturity of the proliferating malignant cell type.⁴ Acute leukemia is the result of the proliferation of immature or blastic cells; chronic leukemia is the result of the proliferation of mature or differentiated cells. Congenital leukemia is much less common and develops during the first month of life. Most childhood leukemias are acute and lymphoblastic in nature; in fact, acute lymphoblastic leukemia (ALL) accounts for approximately 80% of acute leukemias of children and adolescents and AML accounts for the remaining 15% to 20% of cases.^4,5 ALL and AML are further subdivided based on the morphologic analysis of leukemic cells in the marrow.

Although the presentation of acute leukemia can be highly variable, children with the disease generally have a several-week history of some combination of pallor, easy bruising, lethargy, anorexia, malaise, fever, bone pain, arthralgias, abdominal pain, and bleeding. In some, the presentation is acute, with significant bleeding or severe infection; others may be essentially asymptomatic.

Physical examination often reveals pallor, petechiae, ecchymosis, lymphadenopathy, and hepatosplenomegaly. Both ALL and AML are characterized by varying degrees of anemia, thrombocytopenia, and abnormalities of the WBC count. Marrow biopsy is essential for definitive diagnosis. Treatment—comprising chemotherapy and bone marrow transplantation—is tailored to the subtype of disease and individual prognostic variables.

Despite significant advances in diagnosing and treating childhood cancers, leukemia remains, overall, the leading cause of death from disease in children and adolescents.⁶ The treatment of AML has been less successful than the treatment of ALL: Although the 10-year survival rate of children with ALL is reported at greater than 80%, fewer than 50% of children with AML will be cured.^5,6

GEORGE K. SIBERRY, MD, MPH, SECTION EDITOR
Contemporary Pediatrics 9/03

4, Pui C-H, Crist WM: Leukemia, in Rudolf AM, Hoffman JI, Rudolf, CD (eds): Rudolf's Pediatrics, ed 20. Stamford, Conn. Appleton & Lange, 1996, pp 1269–1279

5. Arceci RJ: Progress and controversies in the treatment of pediatric acute myelogenous leukemia. Curr Opin Hematol 2002;9:353

6. Reaman GH: Pediatric oncology: Current views and outcomes. Pediatr Clin North Am 2002;49:1305