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SEER Inquiry System - Report
Produced: 09/19/2026 7:01 PM
Question 20120061
Inquiry Details
References:
2007 MP/H Rules
Question:
MP/H Rules/Multiple Primaries--Ovary: How many primaries are accessioned and which multiple primary rule applies for a patient diagnosed with a carcinosarcoma of the left ovary and a serous carcinoma of the right ovary? See Discussion.
Discussion:
The patient underwent a debulking surgery showing a 20.5 cm carcinosarcoma with focal areas of high grade serous carcinoma and extensive high grade stromal sarcoma in the left ovary. The right ovary showed only a high grade serous carcinoma with extensive involvement of the ovarian parenchyma but no sarcomatous elements. While carcinosarcoma is composed of both epithelial and non-epithelial elements, does the presence of a purely epithelial tumor in the contralateral ovary indicate these are separate primaries per rule M8?
Answer:
For cases diagnosed 2007 or later, accession two primaries, carcinosarcoma [8980/3] of the left ovary and serous carcinoma [8441/3] of the right ovary.
The steps used to arrive at this decision are:
Open the Multiple Primary and Histology Coding Rules Manual. Choose one of the three formats (i.e., flowchart, matrix or text). After determining the histology of each tumor (8980/3 and 8441/3), go to the Other Sites MP rules because ovary does not have site specific rules developed
Start at the MULTIPLE TUMORS module, Rule M3. The rules are intended to be reviewed in consecutive order within a module. Stop at the first rule that applies to the case you are processing.
Review Table 1 (Paired Organs and Sites with Laterality) to determine whether ovary is a paired site. To locate Table 1, go to Other Site under the Terms & Definitions section of the manual. Ovary is listed as a paired site. Accession multiple primaries when there are tumors on both sides (right and left) of a site listed in Table 1 (Paired Organs and Sites with Laterality).
Carcinosarcoma [8980/3] is not an epithelial tumor of the ovary within the range of 8000-8799 and, therefore, Rule M7 does not apply.
