This manual replaces the previously posted 2018 Solid Tumor Manual and should be used for coding cases diagnosed January 1, 2018 and forward; see exceptions for Melanoma and Other Sites below.

Use the 2018 Solid Tumor coding rules to determine the number of primaries to abstract and the histology to code for cases diagnosed 1/1/2018 and forward. The Solid Tumor coding rules and the 2018 General Instructions replace the 2007 Multiple Primary & Histology (MP/H) Rules for the following sites ONLY:

  • 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

2021 Cutaneous Melanoma Rules

Use the 2021 Solid Tumor Cutaneous Melanoma rules to determine the number of primaries to abstract and the histology to code for cases diagnosed 1/1/2021 forward. The Solid Tumor Cutaneous Melanoma coding rules and the 2018 General Instructions replace the 2007 Multiple Primary & Histology (MP/H) Rules beginning 1/1/2021.

Revision status for remaining 2007 Multiple Primary and Histology site rules:

We are currently working on revisions to the Other Sites MP/H module. Release date has not yet been determined.  The 2007 MP/H and 2007 General Instructions are to be used, with a few exceptions, for cases for the following site groups until instructed to do otherwise:

Other Sites:

The following primary sites are excluded for 1/1/2018 forward:

  • Rectosigmoid and rectum which are included in 2018 Colon rules
  • Peripheral nerves which are included in the 2018 Malignant CNS rules

We have identified the need to separate select sites into individual modules. These site-specific rules may be individual sections within the Other sites rules, or free-standing modules. The following sites have been determined to need additional rules: GYN, GI (excluding colorectal), Thyroid, Soft tissue/bone, and Male genital.

Download the Solid Tumor Modules

Cutaneous Melanoma and updated General Instructions posted November 5, 2020; All other sections were updated on July 17, 2019.

Use the 2007 General Instructions, Other Sites for cases diagnosed 2007-2021.

Revision History

The change log contains updates made in 2020. Please see the Revision Archive for earlier changes.

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. (July 2019). Solid Tumor Rules. National Cancer Institute, Rockville, MD 20850.