SEER Inquiry System - Question 20120018 Details

Code the histology to duct and lobular carcinoma in situ [8522/2].

For cases diagnosed 2007 and later, the steps used to arrive at this decision are:

Go to the Breast MP rules found in the Multiple Primary and Histology Coding Rules Manual. Start at the MULTIPLE TUMORS Module Rule M4 because the patient had multiple foci of DCIS and a separate, single focus of LCIS. The rules are intended to be reviewed in consecutive order within the applicable Module. Tumors that are lobular and duct are a single primary.

Go to the Breast Histology rules found in the Multiple Primary and Histology Coding Rules Manual. Start at the MULTIPLE TUMORS ABSTRACTED AS A SINGLE PRIMARY Module Rule H20 because the patient has multiple foci of DCIS and LCIS. Code the histology as 8522/2 [duct and lobular carcinoma in situ] when there is any combination of lobular [8520] and duct carcinoma.

The DCIS and LCIS are separate tumors. The DCIS was removed by the lumpectomy and the LCIS by the mastectomy. The most representative specimen for the DCIS is the lumpectomy. The most representative specimen for the LCIS is the mastectomy. Both pathology reports must be used in this case to determine the histology.