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SEER Inquiry System - Report
Produced: 12/28/2024 12:22 PM
Question 20210069
Inquiry Details
References:
#1: 2018 EOD Manual. Bile ducts intrahepatic
#2: 2018 Summary Stage. Intrahepatic Bile Duct
Question:
EOD 2018/Summary Stage 2018--Intrahepatic Bile Duct: How should Extent of Disease (EOD) Primary Tumor (PT) be coded for invasion of or into (but not through) the visceral peritoneum for an intrahepatic bile duct primary? See Discussion.
Discussion:
Invasion of the visceral peritoneum is Regional (code 2) in Summary Stage. EOD PT code 500 is for invasion BEYOND the visceral peritoneum into adjacent connective tissues, and maps to T3 and Regional Summary Stage, but that code seems too extensive. All lower EOD codes map to Localized Summary Stage.
Answer:
Assign code 500 for EOD Primary Tumor for now.
We have confirmed with AJCC that "invasion of" but not "through" the visceral peritoneum maps to a T2 and not T3. Involvement of the visceral peritoneum for Summary Stage is Regional and does not make a distinction between "invasion of" or "invasion through." Any involvement of the visceral peritoneum is regional.
To correct this situation would require a new code, which would derive a T2/RE. That code will be added to the updates for 2023.
Code 500 will derive the appropriate Summary Stage of 2 (Regional). We are aware that this will derive the incorrect T; however, there is no work around at this time that will derive the correct T and Summary Stage, so we are defaulting to deriving the correct Summary Stage.
