Based on questions and continued suggestions from registrars and educators, the decision was made to update the applicable rules at this time. Most changes are minor: terminology, additional definitions, and new notes and examples.
We recommend you read the July 2019 Change Log to understand what changes were made.
Lung H rule:
SEER identified an issue with lung histology reporting by pathologists and after consulting with our expert lung pathologist, determined that a rule should be added to specifically address this issue.
The new lung H rule addresses tumors with multiple types of adenocarcinoma and percentages of each type listed in the diagnosis. The original H rule instructed registrars to code adenocarcinoma, mixed types (8255/3). Per our lung expert, ICD-O code 8255/3 is strongly discouraged. The new H rule provides instructions on coding the histology comprising the greatest percentage of tumor. Lung Table 2 (Combination histology codes) has also been updated to reinforce the new H rule.
Important: We strongly suggest you review lung cases diagnosed 1/1/2018 forward with code 8255/3 to determine if a specific histology code can be assigned based on the new H rule. By coding a specific histology rather than the mixed histology, you will be able to assign stage.
Lung M rule:
A rule was added to address separate non-contiguous tumors, one with a combination code from Table 2 and one with a single histology from Table 3.
A comprehensive change log has also been posted for reference.
The updated rules published July 2019 apply to the following sites only:
Head & Neck
Submit questions concerning the Solid Tumor Rules to Ask A SEER Registrar:
Senior Editor, Solid Tumor Manual