C21.0
BillableMalignant neoplasm of anus, unspecified
Malignant neoplasm of anus, unspecified
Coding Notes
Excludes 1
Codes that cannot be used together with this code (mutual exclusion)
Excludes 2
Conditions not included here, but the patient may have both
- •gastrointestinal stromal tumorsA-)C49
- malignant carcinoid tumors of the colon (C7A.02-)
- •malignant melanoma of anal marginC43.51
- •malignant melanoma of anal skinC43.51
- •malignant melanoma of perianal skinC43.51
- •other and unspecified malignant neoplasm of anal margin, , ,C44.500, C44.510, C44.520, C44.590
- •other and unspecified malignant neoplasm of anal skin, , ,C44.500, C44.510, C44.520, C44.590
- •other and unspecified malignant neoplasm of perianal skin, , ,C44.500, C44.510, C44.520, C44.590
Related Codes(3)
ICD-11 Equivalents(1)
ICD-11 Equivalents
View full mappingCorresponding ICD-11 codes from the WHO crosswalk mapping
Also Known As / Clinical Terms(65)
SNOMED CT
- Primary malignant neoplasm of anus93676009
- Malignant neoplasm of rectum, rectosigmoid junction and anus187760008
- Malignant neoplasm of rectosigmoid junction363414004
- Malignant tumor of rectosigmoid junction363414004
- Malignant tumour of rectosigmoid junction363414004
- Rectosigmoid colon cancer363414004
- Malignant neoplasm of anus363490009
- Malignant tumor of anus363490009
- Malignant tumour of anus363490009
- Adenocarcinoma of anus423607006
- Adenocarcinoma of anorectum447886005
- Anorectal adenocarcinoma447886005
- Carcinoma of anus448315008
- Malignant epithelial neoplasm of anus448315008
- Primary squamous cell carcinoma of anus723265000
- Lymphoma of anus1153356005
- Malignant mesenchymal neoplasm of anus1156811000
- Primary malignant mesenchymal neoplasm of anus1254825003
- Primary adenocarcinoma of anus184741000119107
- Primary sarcoma of perineum688061000119104
UMLS
- Malignant Anal NeoplasmC0153446
- Malignant Anal TumorC0153446
- Malignant Neoplasm of AnusC0153446
- Malignant Neoplasm of the AnusC0153446
- Malignant Tumor of AnusC0153446
- Malignant Tumor of the AnusC0153446
- Malignant neoplasm of anusC0153446
- Malignant neoplasm of anus (disorder)C0153446
- Malignant neoplasm of anus, unspecifiedC0153446
- Malignant tumor of anusC0153446
- Malignant tumour of anusC0153446
- anal cancerC0153446
- anal cancersC0153446
- anus cancerC0153446
- cancer anusC0153446
- cancer of the anusC0153446
Clinical Terms
- Primary malignant mesenchymal neoplasm of anus
- Anorectal adenocarcinoma
- Adenocarcinoma of anorectum
- Primary sarcoma of perineum
- Malignant Neoplasm of the Anus
- Malignant tumour of rectosigmoid junction
- Primary adenocarcinoma of anus
- Malignant tumor of rectosigmoid junction
- Malignant epithelial neoplasm of anus
- Malignant Anal Neoplasm
- cancer anus
- Rectosigmoid colon cancer
- cancer of the anus
- Malignant Anal Tumor
- Malignant tumour of anus
- anal cancers
- Adenocarcinoma of anus
- Lymphoma of anus
- Malignant Tumor of Anus
- Primary squamous cell carcinoma of anus
- Carcinoma of anus
- Malignant Tumor of the Anus
- Malignant neoplasm of anus (disorder)
- Malignant neoplasm of rectosigmoid junction
- Malignant neoplasm of rectum, rectosigmoid junction and anus
- Primary malignant neoplasm of anus
- anus cancer
- anal cancer
- Malignant mesenchymal neoplasm of anus
Frequently Asked Questions
What is the ICD-10 code for malignant neoplasm of anus, unspecified?
The ICD-10-CM code for malignant neoplasm of anus, unspecified is C21.0. The full clinical description is "Malignant neoplasm of anus, unspecified". C21.0 is a billable/specific code that can be used on insurance claims and medical billing.
What does ICD-10 code C21.0 mean?
ICD-10-CM code C21.0 represents “Malignant neoplasm of anus, unspecified”. It is classified under Chapter 2: Neoplasms and is a billable/specific code that can be used on a claim.
Is C21.0 a billable code?
Yes, C21.0 is a billable/specific ICD-10-CM code and can be used to indicate a diagnosis on a medical claim.
What chapter is C21.0 in?
C21.0 is in Chapter 2: Neoplasms (codes C00-D49).
What codes cannot be used with C21.0?
C21.0 has Excludes1 notes indicating codes that cannot be used together with it, including: Kaposi's sarcoma of gastrointestinal sites (C46.4).
What SNOMED CT codes does C21.0 map to?
C21.0 maps to 13 SNOMED CT concepts: 447886005, 423607006, 448315008, 1153356005, 1156811000, and 8 more. SNOMED CT is a clinical terminology used in electronic health records.
What are the UMLS CUIs for C21.0?
C21.0 is linked to 1 UMLS Concept Unique Identifier: C0153446. The UMLS (Unified Medical Language System) integrates multiple biomedical vocabularies maintained by the U.S. National Library of Medicine.
How does C21.0 relate to ICF functioning codes?
ICF (International Classification of Functioning, Disability and Health) codes describe how conditions like malignant neoplasm of anus, unspecified affect a person's functioning — body functions, activities, participation, and environmental factors. AutoICD provides ICF Core Sets for 12+ conditions and can map clinical text to ICF categories automatically. Browse the ICF directory to explore functioning codes.
What is the ICD-11 equivalent of C21.0?
C21.0 maps to the ICD-11 code: 2C00.Z (Malignant neoplasms of anus or anal canal, unspecified).
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Includes SNOMED Clinical Terms® (SNOMED CT®) used by permission of SNOMED International. Includes content from the UMLS Metathesaurus, courtesy of the U.S. National Library of Medicine.