Acute Lymphoblastic Leukemia (ALL) Flashcards
most common types of leukemia in children
- ALL (acute lymphoblastic leukemia) ~80%
- AML (acute myeloid leukemia) ~15%
- CML (chronic myeloid leukemia) ~4%
acute vs. chronic leukemias
*acute: predominance of immature WBC precursors; these cells proliferate and LACK DIFFERENTIATION
*chronic: proliferation of relatively mature (differentiated) WBCs; often indolent; much more commonly seen in adults than children
ALL (acute lymphoblastic leukemia) - epidemiology
*ALL is the single most common childhood malignancy, accounting for 25% of all childhood cancers
*hispanics > whites > blacks
*males > females
clinical manifestations of ALL (acute lymphoblastic leukemia)
*fatigue
*pallor
*bruising, bleeding
*fever
*lymphadenopathy
*hepatosplenomegaly
*mediastinal mass
*pain (musculoskeletal)
lab findings of ALL (acute lymphoblastic leukemia)
*WBC count may be normal, high (leukocytosis) or low (leukopenia); may see blasts on the blood smear
*anemia (low Hb/Hct)
*thrombocytopenia (low platelets)
*may see chemical abnormalities consistent with “tumor lysis” (increased uric acid, phosphorous, potassium, creatinine)
differential dx for ALL (acute lymphoblastic leukemia)
*infection (EBV or other viruses)
*immune thrombocytopenic purpura (ITP)
*juvenile idiopathic arthritis
*aplastic anemia
*other malignancies (lymphoma, neuroblastoma)
diagnosis for ALL (acute lymphoblastic leukemia)
*bone marrow aspirate: 20% or more of lymphoblasts in bone marrow = acute leukemia
*4-19% may be myelodysplasia
*lumbar puncture also required for evaluation of CNS disease (looking for blasts in CSF)
classification of ALL (acute lymphoblastic leukemia)
*marrow is usually hypercellular (lots of blasts, few normal cells)
*microscopy: assess morphology of cells
*immunophenotyping (flow cytometry) - monoclonal antibodies reacting with cell surface antigens [helps distinguish ALL vs. AML, T vs. B lineage]
*genetic testing of leukemia cells (cytogenetics, FISH, PCR)
good prognostic factors for ALL (acute lymphoblastic leukemia)
*age 1-10 years
*highest pre-treatment WBC count on a CBC < 50,000
*somatic findings associated with a favorable prognosis:
-hyperdiploidy (>50 chromosomes per leukemia cell)
-t(12;21) translocation
-trisomies of chromosomes 4, 10, and 17
bad prognostic factors for ALL (acute lymphoblastic leukemia)
*age < 1 year or 10+ years
*highest pre-treatment WBC counts on a CBC > 50,000
*somatic findings associated with an unfavorable prognosis:
-hypodiploidy (<44 chromosomes per leukemia cell)
-KMT2A gene rearrangement
-t(9;22) translocation (Philadelphia chromosome)
T lymphoblastic leukemia / T cell ALL - common findings
*males > females
*older age than B-ALL (5-12 years, but may be older or younger)
*high WBC conut
*bulky adenopathy, MEDIASTINAL MASS, hepatosplenomegaly
*CNS disease
emergencies associated with ALL (acute lymphoblastic leukemia)
*sepsis (infection)
*bleeding (from thrombocytopenia)
*tumor lysis syndrome (elevated uric acid, potassium, phosphorus, creatinine)
*hyperleukocytosis (very high WBC count)
*tracheal compression/superior vena cava (SVC) syndrome
basic principles for treatment of ALL (acute lymphoblastic leukemia)
*multi-agent chemotherapy is key:
*4 major phases of therapy:
1. induction (1 month)
2. consolidation (2-6 months)
3. delayed intensification (2 months)
4. maintenance (~2 years)
note: CNS treatment is delivered throughout ALL phases:
a. intrathecal chemo (methotrexate most common)
b. radiation therapy (in select cases)
commonly used drugs to treat ALL (acute lymphoblastic leukemia)
*steroids (prednisone, dexamethasone)
*vincristine
*asparaginase
*doxorubicin/daunorbuicin
*methotrexate
*mercaptopruine
*cytarabine
*cyclophosphamide
hematopoietic cell transplant for ALL (acute lymphoblastic leukemia)
*reserved for very high risk patients in first remission, selected patients with relapsed ALL
*potential donors:
-matched sibling
-matched unrelated donor
-umbilical cord blood
-haploidentical donor (parent or sibling)
