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SEER Inquiry System - Report
Produced: 12/12/2025 12:03 PM
Question 20051131
Inquiry Details
References:
ICD-O-3
Question:
Recurrence/Multiple Primaries (Pre-2007)/Primary Site--Breast: Is a malignancy that occurs in 2005 in a mastectomy scar years following an original diagnosis of breast cancer in 1971 a recurrence (not reportable) or a new primary (breast or chest wall, NOS)? See Discussion.
Discussion:
The patient had a right mastectomy for breast carcinoma in 1971. In 2005, she came in with a mass in the right axilla and a right chest wall mass in the mastectomy scar. Excision of the axillary mass and biopsy of the chest wall mass revealed invasive adenocarcinoma with a similar histologic pattern. The axilla specimen contained no benign breast tissue. IHC stains exhibit strongly positive for ER, mildly positive for PR and negative for HER2/neu. The pathologist says "Although these findings are consistent with recurrent breast carcinoma, they are not specific for such. Recurrence after 34 yrs. is most unusual."
Answer:
For tumors diagnosed prior to 2007:
The 2005 diagnosis is a new primary. The 1971 site differs from the 2005 site and there are more than two months between the two. Without further information, assign topography code C761 [chest wall]. The pattern of spread, including regional extension, is different for a primary of the chest wall compared to a primary in the breast. Coding the primary site to C761 will group this case with similar cases.
If further information can be obtained, look for old records that describe the extent of the 1971 mastectomy. It is possible that there was breast tissue left on the chest wall. Residual breast tissue is often present following mastectomy (simple, modified, or even radical). New carcinoma can develop in the remaining breast tissue.
For tumors diagnosed 2007 or later, refer to the MP/H rules. If there are still questions about how this type of tumor should be coded, submit a new question to SINQ and include the difficulties you are encountering in applying the MP/H rules.
