Table 2. Definitions of TNM Stage I through Stage IVa
| Stage | Tumor Grade | Tumor Size |
| IA | Low | <8 cm |
| IB | Low | >8 cm |
| IIA | High | <8 cm |
| IIB | High | >8 cm |
| III | Any tumor grade, skip metastasesb | |
| IV | Any tumor grade, any tumor size, distant metastases | |
| aReprinted with permission from AJCC: Bone. In: Edge SB, Byrd DR, Compton CC, et al., eds.: AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer, 2010, pp 281-90. | ||
| bSkip metastases: discontinuous tumors in the primary bone site. |
