Carcinoma in situ of unspecified part of intestine

This code signifies the presence of abnormal, non-invasive epithelial cells that are confined to the mucosal layer of an unspecified part of the intestine. These cells exhibit features of malignancy but have not yet invaded beyond the basement membrane. It represents a pre-invasive stage of cancer.

This code is appropriate when pathology reports confirm carcinoma in situ within the intestine, but the specific anatomical location (e.g., small intestine, large intestine, rectum) is not documented. It is typically used for initial diagnosis or follow-up when the precise site remains undetermined.

• Avoid using this code if a more specific intestinal site (e.g., D01.0 for colon, D01.1 for rectum) is documented.
• Ensure the pathology report explicitly states "carcinoma in situ" and not dysplasia or adenoma without in situ features.
• Query the provider for a more specific anatomical location if possible to allow for more precise coding.