Neuroblastoma

Basics

Neuroblastoma is usually exclusively a disease of children and is an umbrella term that is used to refer to a spectrum of neuroblastic tumors that arise from embryonic sympathetic ganglion cells; furthermore, they have the capacity to synthesize and ultimately secrete catecholamines.

Description

Neuroblastomas arise from neural crest tissue and function similarly to paragangliomas and pheochromocytomas. Clinical activity varies from benign tumors that spontaneously regress to aggressive metastatic disease.

  • Primary tumor location (1):
    • Adrenal medulla—40%
    • Sympathetic ganglia:
      • Abdominal—25%
      • Thoracic—15%
      • Cervical—5%
      • Pelvic—5%
    • Other—10%
  • Sites of metastasis: bone—specifically to sphenoid bone and retrobulbar tissue, bone marrow, regional/disseminated lymph nodes, liver, subcutaneous tissue producing blue subcutaneous nodules

Epidemiology

  • Third most common pediatric malignancy
  • Most common tumor in infants <1 year of age
  • Accounts for 6% of all childhood cancers (2)
  • Most common solid neoplasm outside of the CNS
  • Predominant age at diagnosis
    • Within 2 years of life: 50%
    • Within first 5 years of life: 90%
    • Median age 17.3 months
  • Older children are at higher risk for metastatic disease and have a poorer prognosis.
  • Screening has no impact on mortality.

Incidence

  • 800 new cases of neuroblastoma each year in United States (1)
  • From birth to age 1 year in the United States: 52.1 cases per million children per year (1)
  • From age 1 to 4 years in the United States: 19.1 cases per million children per year
  • First 15 years of life in the United States: 9.8 cases per million children per year

Etiology and Pathophysiology

Genetics

  • 80% of tumors have genetic abnormalities.
  • Autosomal dominant inheritance pattern
  • Mutations in anaplastic lymphoma kinase (ALK) oncogene and PHOX2B account for the majority of hereditary neuroblastoma (2,3).
  • MYCN oncogene amplification and mutations at chromosome 11q are used as markers for prognostication and treatment stratification (3).
  • Other genetic mutations associated with increased susceptibility for disease (3):
    • FLJ22536
    • BARD1
    • NBPF23
  • DNA ploidy: Hyperdiploidy in infants <1 year of age is associated with excellent long-term survival; diploidy is associated with treatment failure.

Risk Factors

  • Maternal phenytoin or opiates
  • Folate deficiency
  • Opsoclonus–myoclonus syndrome
    • 50% have neuroblastoma.
  • Beckwith-Wiedemann syndrome
  • Pancreatic islet cell dysplasia
  • Fetal alcohol syndrome
  • Hirschsprung disease
  • Family history of neuroblastoma
  • Neurofibromatosis type 1
  • Congenital central hypoventilation syndrome
  • Gestational diabetes mellitus

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