Neuroblastoma

Snapshot

• A 3-year-old girl is brought to the emergency room after her parents felt an abdominal mass during her bath. She is asymptomatic except for the mass, which is irregular, firm, and clearly crosses the midline, ruling out Wilms tumor. A week later, a biopsy of the mass comes back with rosette formation seen on histology and small round blue cells.

Introduction

• Malignant tumor from cells of sympathetic nervous system
  • most commonly in adrenal medulla and paraspinal region
  • most common adrenal tumor in kids 
    • vs pheochromocytoma, which is most common in adults
• Epidemiology
  • in < 4 years old
• Pathogenesis
  • neural crest cell origin
  • anywhere along sympathetic chain
• Genetics
  • associated with amplification of N-Myc oncogene 
  • nuclear transcription factor
• Associated conditions
• opsoclonus myoclonus syndrome

Presentation

• Symptoms
  • abdominal distention
  • abdominal pain
• Physical exam
  • palpable firm and irregular mass
    • crosses midline (vs Wilms tumor which is unilateral and smooth)
  • may have diastolic hypertension
  • opsoclonus (dancing eyes) – hallmark of disease
• myoclonus (dancing feet) – hallmark of disease

Evaluation

• Biopsy
  • histology
    • Homer-Wright rosettes
    • small round blue/purple cells
    • Bombesin +
      • stimulates neuroblastoma growth and expression of angiogenic markers
• Urine
  • ↑ homovanillic acid (breakdown product of dopamine)
• ↑ vanillyl mandelic acid (breakdown product of norepinephrine and epinephrine)

Differential Diagnosis

• Wilms tumor 
• Rhabdomyosarcoma
• Germ cell tumors
• Hepatoblastoma

Treatment

• Surgical resection

Prognosis, Prevention, and Complications

• Prognosis
  • younger patients with better prognosis (except for newborns)
  • low n-myc associated with better prognosis
• Complications
  • metastases to bone and skin