Malignant neoplasm of anal canal
Billable / specificHCC V28 22
C21.1 is a billable, specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes in FY2027.
Inclusion terms
Applicable to
- Malignant neoplasm of anal sphincter
Includes (from C21)
- Note: Functional activity
- Note: All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
- Note: Morphology [Histology]
- Note: Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
- Note: Primary malignant neoplasms overlapping site boundaries
- Note: A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
- Note: Malignant neoplasm of ectopic tissue
- Note: Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).
Excludes1
Not coded here — never report together with this code.
Excludes2
Not included here — may be reported together when both conditions exist.
- gastrointestinal stromal tumors (C49.A-) (from C21)
- malignant carcinoid tumors of the colon (C7A.02-) (from C21)
- malignant melanoma of anal margin (C43.51) (from C21)
- malignant melanoma of anal skin (C43.51) (from C21)
- malignant melanoma of perianal skin (C43.51) (from C21)
- other and unspecified malignant neoplasm of anal margin (C44.500, C44.510, C44.520, C44.590) (from C21)
- other and unspecified malignant neoplasm of anal skin (C44.500, C44.510, C44.520, C44.590) (from C21)
- other and unspecified malignant neoplasm of perianal skin (C44.500, C44.510, C44.520, C44.590) (from C21)
Also known as
- Malignant neoplasm of anal sphincter
Parent code
- C21Malignant neoplasm of anus and anal canalHeader