Pathophysiology
1) malignant tumor of neural crest origin, from adrenal medulla or sympathetic ganglia 2) 33% of tumors occur in adrenals, 33% in abdomen, 20% in posterior mediastinum 3) metastasizes to regional lymph nodes, lungs, bone, liver, eye
Signs and Symptoms
1) common presenting sign is an enlarging abdominal mass with calcification 2) ascites from liver metastases 3) pain and irritability from bone metastases 4) respiratory distress from lung compression 5) gait and sphincter problems
Characteristic Test Findings
Laboratory – 1) increased urinary catecholamines – norepinephrine, VMA, HVA, dopamine 2) increased secretion of VIP
Histology/Gross Pathology
1) differentiating neuroblasts (small, round, blue cells) 2) mature ganglion cells (more mature tumors have higher proportion of ganglion cells) 3) rosettes and pseudorosettes (Homer-Wright rosettes)
Associated Conditions
1) deletions on chromosome 1 (1p35-36) 2) duplications on chromosome 2 3) affected gene is N-myc (which can be amplified, depending on differentiation
Inheritance/Epidemiology
1) mostly sporadic inheritance 2) 10% of childhood cancers 3) usually occurs before age 3 years 4) best prognosis – presents < age 2 years, extra-adrenal location, highly differentiated, VMA/HVA > 1, TRK gene expression
Treatment
1) if isolated mass, surgical resection 2) if metastatic, chemotherapy/radiation
Tips for USMLE
1) if question mentions a 2 month-old child with a large abdominal mass (with calcification on radiograph) that suddenly shrinks, think neuroblastoma 2) neuroblastomas “cross the midline,” whereas Wilms’s tumors do not
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