Reminder: Histology Coding Changes for Colorectal Primaries Involving Polyps
Effective with 2018 cases, the following histology codes are no longer used for colorectal cases (C18.0 - C20.9) involving a polyp:
- 8210 Adenocarcinoma in adenomatous polyp
- 8263 Adenocarcinoma in a tubulovillous adenoma
- 8261 Adenocarcinoma in villous adenoma
Reference: Solid Tumor Rules - Colon, Rectosigmoid, and Rectum
Item #7 in the "Changes from 2007 MPH Rules" section
- Polyps are now disregarded when coding histology. For example, adenocarcinoma in an adenomatous polyp is coded as adenocarcinoma 8140. For the purposes of determining multiple primaries, tumors coded as adenocarcinoma in a polyp for pre-2018 cases should be treated as adenocarcinoma 8140.
Rule H2
- Code the histology and ignore the polyp when a carcinoma originates in a polyp.
- Note 1: This is a change from the 2007 MPH rules which instructed registrars to use the codes for malignancies in a polyp, such as adenocarcinoma in a polyp 8210.
- Note 2: Sufficient data has been collected to:
- Determine the frequency with which carcinomas arise within polyps.
- Establish patient care guidelines for individuals with colon polyps.
