Primary Size Extension
Important
These modules are archived and should only be referenced for historical purposes.
Primary Sites Where Tumor Size Is Required for AJCC Staging
In order to classify the T category for certain sites, it is necessary to know the size of the primary tumor, usually for T1 - T3. For the following sites and site categories, the size of the primary tumor must be recorded in order to assign the T category and derive a stage group:
| Code | Site | |
|---|---|---|
| Lip and oral cavity | ** 7 sites ** | |
| Oropharynx | ** 3 sites ** | |
| Hypopharynx | ||
| Major salivary glands | ** 3 sites ** | |
| Thyroid | ||
| Anal canal | ||
| Liver and intrahepatic bile ducts | ||
| Pancreas | ** 3 sites ** | |
| Lung | ||
| Bone | ||
| Soft tissue sarcoma | ** 3 sites ** | |
| Skin |
Suggested Citation
SEER Training Modules: Primary Size Extension. U.S. National Institutes of Health, National Cancer Institute. Cited 19 December 2025. Available from: https://training.seer.cancer.gov.