Malignant neoplasm of anal canal

This code represents a primary cancerous tumor originating in the anal canal, the terminal section of the large intestine connecting the rectum to the anus. This malignancy typically arises from the squamous cells lining the anal canal but can also originate from glandular tissue.

Apply this code for confirmed diagnoses of primary malignant neoplasms located specifically within the anal canal. Documentation should clearly state the anatomical site as the anal canal, distinguishing it from tumors of the rectum or anus. Pathological reports confirming malignancy are essential for accurate coding.

• Differentiate carefully between anal canal, anal margin, and rectum; each has distinct ICD-10-CM codes.
• Do not use this code for secondary or metastatic cancers to the anal canal; use appropriate secondary malignancy codes.
• Always sequence this code as the primary diagnosis when it is the reason for the encounter or treatment.