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Produced: 02/14/2026 5:10 AM
Question 20130198
Inquiry Details
References:
2007 MP/H Rules
Question:
MP/H Rules/Multiple primaries--Rectosigmoid: How many primaries are accessioned for a synchronous diagnosis of neuroendocrine carcinoma and a separate adenocarcinoma arising in a villous adenoma when both arise in the rectosigmoid junction? See Discussion.
Discussion:
Total colectomy showed neuroendocrine carcinoma of the rectosigmoid junction, as well as a separate adenocarcinoma arising in a villous adenoma of the rectosigmoid junction. Is this a single primary per Rule M13 (a frank adenocarcinoma and an adenocarcinoma in a polyp) or Rule M16 (adenocarcinoma and a more specific adenocarcinoma)? Or are these two primaries?
Answer:
Accession two primaries per Rule M17, neuroendocrine carcinoma [8246/3] of the rectosigmoid junction [C199], and adenocarcinoma in a villous adenoma [8261/3] of the rectosigmoid junction [C199]. There are two tumors with ICD-O-3 histology codes that differ at the third number.
Rule M13 does not apply to neuroendocrine carcinoma. Rule M16 does not apply to this case because there are two specific histologies.
Cancer Site Category:
N/A
Data Item Category:
N/A
Other Category:
Multiple primaries
Year:
2013
