International neuroblastoma staging system

StageDescription
1localized tumor confined to area of origin; complete gross resection with or without microscopic residual disease; identifiable ipsilateral and contralateral lymph nodes negative macroscopically
2Alocalized tumor with incomplete gross excision; identifiable ipsilateral and contralateral lymph nodes negative microscopically
2Bunilateral tumor with complete or incomplete gross resection with positive ipsilateral regional lymph nodes; contralateral lymph nodes negative microscopically
3tumor infiltrating across the midline with or without regional lymph node involvement; unilateral tumor with contralateral regional lymph node involvement; midline tumor with bilateral lymph node involvement
4dissemination of tumor to bone, bone marrow, liver, distant lymph nodes or other organs
4slimited to infants below 1 year of age. Localized primary tumor as defined for stage 1 or 2A or 2B with dissemination limited to liver, skin and/or bone marrow