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SEER Inquiry System - Report
Produced: 09/16/2026 7:27 AM
Question 20061068
Inquiry Details
References:
ICD-O-3
Question:
Primary Site--Unknown & ill-defined site: Should the primary site be coded to C809 [Unknown primary site] or C761 [Thorax, NOS] if the patient died following a limited work-up that included on a cytology on pericardial fluid that was positive for poor differentiated adenocarcinoma?
Discussion:
Answer:
Based on the information provided, code the primary site to C809 [Unknown primary site]. There is not enough information provided to suggest that the primary site is the thorax or any other location.
Cancer Site Category:
Unknown & ill-defined sit
Data Item Category:
Primary site
Other Category:
N/A
Year:
2006
