01-30-2026
Scenario: Diagnosed
CT A/P- Impression: No acute intrathoracic process. Extensive metastatic disease of the liver.
Liver bx: Involved by poorly differentiated carcinoma. Comment: The tumor morphology and immunoprofile are non-specific. The differential diagnosis includes metastatic carcinoma from the upper GI and pancreatobiliary origin.
Hem Onc note: Image-guided bx confirmed metastatic poorly differentiated carcinoma. The differential diagnosis includes metastatic carcinoma from the upper GI tract and pancreatobiliary origin.
Question: How would you assign the Primary Site?
- C22.0 Liver; hepatic, NOS
- C22.1 Intrahepatic bile duct
- C25.9 Pancreas, NOS
- C26.0 Intestinal tract, NOS
- C26.9 Gastrointestinal tract, NOS
- C80.9 Unknown Primary Nos
Answer: C26.9 Gastrointestinal tract, NOS
ICD0-3 Coding guidelines for topography and morphology
SINQ https://seer.cancer.gov/seer-inquiry/inquiry-detail/20061034/ Code the primary site according to the physician’s opinion. An ill-defined site code or an NOS code for the organ system is preferred over C809 [Unknown primary site] whenever possible. Code C809 only when there is not enough information to use an ill-defined or NOS code.
SINQ https://seer.cancer.gov/seer-inquiry/inquiry-detail/20140008/
Primary site: If text supports a pancreatobiliary primary with no other information, assign C269 in the absence of any additional information.
