Intraductal carcinoma in situ of left breast

This code signifies the presence of abnormal, non-invasive cancer cells confined to the milk ducts within the left breast. It represents a pre-invasive form of breast cancer, meaning the cells have not spread beyond the duct walls into surrounding breast tissue.

Use this code when pathology reports confirm ductal carcinoma in situ (DCIS) specifically located in the left breast. Documentation should clearly state "intraductal carcinoma in situ" or "DCIS" and specify the laterality as "left breast."

• Ensure the pathology report explicitly states "in situ" and not invasive carcinoma.
• Verify laterality; use D05.11 for the right breast and D05.10 for unspecified breast.
• Do not code with an invasive breast cancer code (e.g., C50.x) unless an invasive component is also identified.