Table 3. Soft Tissue Sarcoma Committee of the Children's Oncology Group: Surgical-pathologic Group System
| Group | Incidence | Definition |
| I | Approximately 13% | Localized tumor, completely removed with microscopically clear margins and no regional lymph node involvement. Lymph node biopsy or sampling is encouraged if lymph nodes are clinically or radiographically suspicious. |
| II | Approximately 20% | Localized tumor, completely removed with: (a) microscopic disease at the margin, (b) regional disease with involved, grossly removed regional lymph nodes without microresidual disease, or (c) regional disease with involved nodes, grossly removed but with microscopic residual and/or histologic involvement of the most distal node from the primary tumor. |
| III | Approximately 48% | Localized tumor, incompletely removed with gross, residual disease after: (a) biopsy only, or (b) gross major resection of the primary tumor (>50%). |
| IV | Approximately 18% | Distant metastases are present at diagnosis. This category includes: (a) radiographically identified evidence of tumor spread, and (b) positive tumor cells in cerebral spinal fluid, pleural, or peritoneal fluids, or implants in these regions. |
