SEER Inquiry System - Report
Produced: 12/26/2024 5:38 AM
Question 20120086
Inquiry Details
References:
2012 SEER Manual. Section IV
Question:
Discussion:
Answer:
Code the primary site to C179 [small intestine, NOS] for multiple invasive tumors of the small intestine accessioned as a single primary.
The steps used to arrive at this decision are:
Step 1: Go to the Primary Site subsection located in Section IV of the 2012 SEER Manual titled "Description of This Neoplasm."
Step 2: Apply instruction 5. "Code the last digit of the primary site code to '9' for single primaries, when multiple tumors arise in different subsites of the same anatomic site and the point of origin cannot be determined." Code the primary site to C179 [small intestine, NOS].
When multiple tumors arising in different subsites are accessioned as a single primary, the primary site is coded to the NOS code, in this case small intestine, NOS [C179]. The level of invasion does not determine the primary site, unless one or more of the tumors is in situ and another is invasive.