Malignant neoplasm of other sites of rectum, rectosigmoid junction, and anus

This code signifies a cancerous tumor originating in various specified areas of the lower gastrointestinal tract, including parts of the rectum, the transitional zone between the rectum and sigmoid colon, and the anus, excluding the anal canal and anal skin. It indicates a primary malignancy affecting these specific anatomical locations.

Use this code for documented primary malignant neoplasms of the rectum (excluding specified parts), rectosigmoid junction, or anus (excluding anal canal and skin). Supporting documentation should clearly identify the tumor's origin within these "other" or unspecified sites of the rectum, rectosigmoid, or anus.

• Ensure documentation specifies the primary site as "other" or unspecified within the rectum, rectosigmoid junction, or anus.
• Distinguish carefully from malignant neoplasms of the anal canal (154.2) or anal skin (172.5, 173.5).
• Always sequence this code as the primary diagnosis when it is the reason for the encounter, unless a metastatic site is being treated.