Carcinoma in situ of other parts of intestine

This code signifies the presence of non-invasive malignant cells confined to the epithelial layer of an intestinal segment other than the colon, rectum, or anus. These abnormal cells have not yet invaded deeper tissues or spread to other parts of the body. It represents an early stage of cancer development within the intestinal lining.

Use this code when pathology reports confirm carcinoma in situ in areas such as the duodenum, jejunum, ileum, or unspecified parts of the small or large intestine (excluding specified colorectal sites). Documentation must clearly state "carcinoma in situ" or "intraepithelial neoplasia" with a high-grade dysplasia equivalent, localized to an intestinal site not covered by more specific D01 codes.

• Ensure the documentation specifies "in situ" and the exact intestinal location to differentiate from invasive carcinoma or benign polyps.
• Do not use this code for carcinoma in situ of the colon, rectum, or anus, as those have more specific D01 codes.
• Confirm the pathology report explicitly states "carcinoma in situ" rather than "severe dysplasia" unless the pathologist equates severe dysplasia to carcinoma in situ.