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SEER Inquiry System - Report
Produced: 01/10/2025 4:59 PM
Question 20230064
Inquiry Details
References:
#1: 2023 SEER Manual, 92-97. Primary Site
#2: ICD-O-3, 45. ICD-O, 3rd edition (purple book)
Question:
Primary Site--Cervix Uteri: When no other information is available regarding the origin of the tumor, can an overlapping cervical adenocarcinoma (C538, 8140/3) be coded to the endocervix (C530) based on the histology? See Discussion.
Discussion:
Adenocarcinoma is a glandular tumor and the endocervix is generally the origin of glandular tissue for the cervix. However, if the only available information is pathology proving a single tumor overlapping the endocervix and exocervix, can we code the site to C530 instead of C538?
Applying the current primary site coding instructions, primary site would be coded as C538 because there is no specific statement of the tumor origin; the primary site coding instructions state the tumor is coded to an overlapping site in the absence of a specific statement of origin and there is no existing SINQ confirming the site can be assumed to be the endocervix based on the histology.
Answer:
Code Primary Site as Overlapping lesion of cervix uteri (C538). The 2023 SEER Program Coding and Staging Manual Primary Site Coding Instructions for Solid Tumors #4 says to code the last digit of the primary site code to ‘8’ when a single tumor overlaps an adjacent subsite(s) of an organ and the point of origin cannot be determined. This is also supported by the ICD-O-3, 3rd edition, note in the Topography section that states: In categories C00 to C809, neoplasms should be assigned to the subcategory that includes the point of origin of the tumor. A tumor that overlaps the boundaries of two or more subcategories and whose point of origin cannot be determined should be classified to subcategory ‘8.”
