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SEER Inquiry System - Report
Produced: 02/06/2026 3:32 AM
Question 20091018
Inquiry Details
References:
#1: 2007 SEER Manual, C-1044, C-1050, C-1060. Appendix C
#2: 2007 SEER Manual, C-517 to C-518, C-704. Appendix C
Question:
Discussion:
For both pleura and fallopian tube, the MP/H rules indicate that bilateral involvement of these sites should be coded as multiple primaries. However, both of these sites have CS extension codes that classify the contralateral disease as regional extension.
Is a case described as a left sided pleural mesothelioma that has right sided pleural disease coded as one or two primaries? How is CS coded?
Answer:
For cases diagnosed 2007 or later:
For a pleural or fallopian tube primary, if there is tumor(s) on the left and separate tumor(s) on the right and neither is stated to be metastatic from the other, abstract as multiple primaries according to rule M8 for other sites. If both sides are involved, but there is only one tumor, rule M2 for other sites applies and this is a single primary. Code each primary separately in CS.
