The 2022 Solid Tumor Rules can be found on the Historical Staging and Coding Manuals page.

Use the Solid Tumor Rules to determine the number of primaries to abstract and the histology to code. The Solid Tumor Rules and General Instructions replace the 2007 Multiple Primary & Histology (MP/H) Rules for the following sites:

  • Breast
  • Colon (includes rectosigmoid and rectum for cases diagnosed 1/1/2018 forward)
  • Head & Neck
  • Kidney
  • Lung
  • Malignant CNS and Peripheral Nerves
  • Non-malignant CNS
  • Urinary Sites
  • Cutaneous Melanoma (for cases diagnosed 1/1/2021 and forward)
  • Other Sites (for cases diagnosed 1/1/2023 and forward)

Other Sites

The Other Sites Solid Tumor Rules should be used for cases diagnosed 1/1/2023 and forward.

For cases diagnosed 1/1/2007-12/31/2022, the 2007 MP/H and 2007 General Instructions are to be used, with a few exceptions.

The following primary sites are excluded from the Other Sites module for 1/1/2018 forward:

  • Rectosigmoid and rectum which are included in Colon Solid Tumor Rules
  • Peripheral nerves which are included in the Malignant CNS Solid Tumor Rules

Download the 2023 Solid Tumor Modules

Revision History

The change log contains updates made in March and May 2023. Please see the Revision Archive for earlier changes including the December 2022 updates.

Histology Coding Clarifications

On occasion, data collection requirements of AJCC and NCI SEER have resulted in conflicting cancer coding instructions for cancer registrars. For more information and specific instructions about reviewing cases already coded, please visit the Histology Coding Clarifications page.

Suggested Citation

Dickie L., Johnson, CH., Adams, S., Negoita, S. (May 2023). Solid Tumor Rules. National Cancer Institute, Rockville, MD 20850.