Unspecified type of carcinoma in situ of unspecified breast

This code signifies the presence of non-invasive breast cancer where the specific histological type (e.g., ductal, lobular) is not documented, and the affected breast is also not specified. It represents a pre-invasive malignancy confined to the epithelial cells, without invasion through the basement membrane.

Use this code when documentation indicates "carcinoma in situ of the breast" without further specification of the type or laterality. This is often an interim diagnosis or when the pathology report is incomplete regarding these details. It is supported by pathology reports confirming in situ carcinoma without further differentiation.

• Avoid using this code if the laterality (left, right, bilateral) or specific type (e.g., D05.1- for lobular, D05.0- for ductal) is documented.
• Query the provider or review the full pathology report for more specific information before assigning this unspecified code.
• This code should be sequenced as the primary diagnosis when the carcinoma in situ is the reason for the encounter.