Site-specific Equivalent Terms, Definitions, Tables & Illustrations

In addition to the General Instructions and the three different formats for the site-specific and "Other Sites" rules themselves, there is one more document that must be downloaded and reviewed for each set of rules: the site-specific equivalent terms, definitions, tables and illustrations. There is a single document containing all of the site-specific documents, but for the sake of abstracting efficiency, when you download this file, separate the various sections and place them with the site-specific rules.

The content of each of the site-specific sections is similar.

  • Introduction
  • Equivalent or Equal Terms
  • Definitions
  • Charts and Tables, if applicable
  • Illustrations

The site-specific Equivalent Terms and Definitions may include a short introduction providing information about the site or body system or instructions for problem areas. For example, for head and neck, the introductory section gives detailed information about how you code the primary site; for example, what do you choose as the primary site?

The second part of this document is the Equivalent or Equal Terms. Similar to the equivalent terms in the general instructions, this section includes site-specific terms that can be used interchangeably.

Following that, there are site-specific definitions. For all sites, this includes descriptions of very frequent histologies or problematic histologies. This section defines important terms and in some cases relates terms to each other. For some sites there is also specific information in this section, for example, about reportability for various malignant melanoma-related terms. A term such as "evolving melanoma" will have a definition, followed by a statement "reportable" or "not reportable". This is included in the MPH rules because reportability was identified as one of the bigger problems that registrars have with malignant melanoma of the skin.

The site-specific Equivalent Terms and Definitions may also have histology charts or tables. These tables are a new concept for registrars. They are referenced in the rules, so it would be a good idea to keep them near the rules. The charts or tables will, in some cases, illustrate histology lineages showing you what terms and codes are related to, or more specific than, other terms. View a chart showing the most common lung histology groups and specific types (PDF) on the SEER web site.

For some sets of rules, there may be tables of paired sites or sites with laterality, such as this example from the head and neck section (PDF).

For some sites there are also combination code tables. So for a combination code such as 8255, adenocarcinoma with mixed subtypes, it would tell you that these are the precise histologies that must be present in the tumor in order to code 8255. This, again, is a new concept. There will be more explanation of the charts and tables when the site-specific rules are covered in more detail later in this module.

View an example of a table defining various combination codes (PDF) on the SEER web site.

And finally, for each of the sites there is a set of anatomic illustrations to orient you to that specific site and give you a little help as you are coding and abstracting, particularly when the case involves multiple primaries. All illustrations are provided for educational purposes for the MPH Rules; some have been licensed by the SEER Program, others have been used with permission of the source.