Table 2.

Staging criteria for pheochromocytoma (modification from INSS staging system)

Stage	Criteria
1	Localized tumor with complete gross excision, with or without microscopic residual disease; representative ipsilateral lymph nodes negative for tumor microscopically (nodes attached to and removed with primary tumor may be positive)
2	Localized tumor with incomplete gross excision; representative ipsilateral nonadherent lymph nodes negative or positive for tumor microscopically
3	Unresectable unilateral tumor infiltrating across the midline (vertebral column) with or without regional lymph node involvement; or localized unilateral tumor with contralateral regional lymph node involvement; or midline tumor with bilateral extension by infiltration (unresectable) or by lymph node involvement
4	Any primary tumor with dissemination to distant lymph nodes, bone, bone marrow, liver, skin and/or other organs (except as defined for stage 4S)
4S	Localized primary tumor (as defined for stage 1, 2) with dissemination limited to skin, liver, and/or bone marrow (limited to infants <1 year of age)