Leukemia (peds)

This page is for pediatric patients. For adult patients, see: leukemia

Background

• Most common cancer in children (33% of all malignancies)
• Most without cause but increased incidence with paternal age, maternal fetal loss, higher birthweight, familial clusters, and some genetic syndromes (Down syndrome)

ALL

• 3/4 of pediatric leukemias
• 5-year survival 75%-80%
• Peak incidence 2-5yr old
• Usually B lineage

AML

• 1/5 of pediatric leukemias
• Worse prognosis
• More complications (more intense chemo treatment required)

Clinical Features

Presentation

• Hepatomegaly and/or splenomegaly with weight loss, abdominal distension or abdominal pain
• Lymphadenopathy
• Fever
• Bleeding (petechiae, purpura), low platelet count, anemia
• MSK pain, limp, refusal to bear weight
• Larger anterior mediastinal mass could cause SVC syndrome

Bone marrow infiltration and failure

• Pallor, fatigue, easy bleeding, fever, infection
• Bone pain/arthralgia
• Hepatomegaly or splenomegaly

Hyperleukocytosis

• Clinically significant when WBC > 200K in AML, >300K in ALL
• Cerebral circulation: headache, altered mental status, visual disturbances, seizure, CVA
• Pulmonary circulation: shortness of breath, hypoxemia

Complications

• Tumor lysis syndrome
• Neutropenic fever, Sepsis, overall increased risk of infection
  • Neutropenic enterocolitis (typhlitis)
• Leukostasis and hyperleukocytosis
• Hyperviscosity syndrome
• Thromboembolism
• Treatment-related complications
  • Chemotherapy-induced nausea and vomiting
  • Cytokine release syndrome
  • Chemotherapeutic drug extravasation
  • Differentiation syndrome (retinoic acid syndrome) in APML
  • Stem cell transplant complications
  • Catheter-related complications
    • Tunnel infection
    • Exit site infection
    • CVC obstruction (intraluminal or catheter tip thrombosis)
    • Catheter-related venous thrombosis
    • Fracture of catheter lumen

Differential Diagnosis

Leukemias will often involve >1 cell line; other conditions restricted to single line

• Aplastic anemia
• Iron deficiency anemia
• Viral infection (EBV, CMV, Parvo), HIV
• Immune thrombocytopenia
• Rheumatologic diseases

Evaluation

• CBC with manual differential
  • If suggestive of leukemia also order:
    • Review of peripheral smear
    • Chemistry, Ca, Phos, Mg, Uric acid, LFTs, LDH, coags, T+S, UCG (if applicable)
    • Viral titers cytomegalovirus, EBV, HIV, HBV, varicella zoster
    • CXRto look for mediastinal mass
    • Consider DIC labs, coag studies

Management

Transfusion

• Options
  • Irradiated: for very immunosuppressed (to prevent graft vs host)
  • Leukocyte-reduced: for patients likely to receive multiple RBC or platelets in future
  • CMV seronegative: for <1yr old, if might need bone marrow transplant in future
• Anemia
  • 10 cc/kg of pRBCs raises hemoglobin by 3 gm/dL
  • Raise hemoglobin to >8
• Thrombocytopenia
  • 0.1 unit/kg platelets results in 30-50K increase in platelet count
  • Risk of spontaneous ICH is extremely low until platelets <5K
  • Transfuse if:
    • Asymptomatic with platelets <10K
    • Invasive procedures require platelets >50K

Leukostasis and Hyperleukocytosis

• Aggressive IV hydration
• Urinary alkalinization (pH 7-7.5)
• Allopurinol (for Tumor Lysis Syndrome (TLS))
• Avoid diuretics and pRBC transfusion (platelets ok)
• Give platelets if <20K
• Leukapheresis

Disposition

• Admit for further workup including bone marrow biopsy and LP

See Also

• Oncologic emergencies
• Leukemia