2017/18 ICD-10-CM Diagnosis Code C21

Malignant neoplasm of anus and anal canal

Type 2 Excludes
Type 2 Excludes Help
A type 2 excludes note represents "not included here". A type 2 excludes note indicates that the condition excluded is not part of the condition it is excluded from but a patient may have both conditions at the same time. When a type 2 excludes note appears under a code it is acceptable to use both the code (C21) and the excluded code together.
  • malignant carcinoid tumors of the colon (
    ICD-10-CM Diagnosis Code C7A.02

    Malignant carcinoid tumors of the appendix, large intestine, and rectum

      2016 2017 2018 Non-Billable/Non-Specific Code
    C7A.02-
    )
  • malignant melanoma of anal margin (
    ICD-10-CM Diagnosis Code C43.51

    Malignant melanoma of anal skin

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Malignant melanoma of anal margin
    • Malignant melanoma of perianal skin
    C43.51
    )
  • malignant melanoma of anal skin (
    ICD-10-CM Diagnosis Code C43.51

    Malignant melanoma of anal skin

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Malignant melanoma of anal margin
    • Malignant melanoma of perianal skin
    C43.51
    )
  • malignant melanoma of perianal skin (
    ICD-10-CM Diagnosis Code C43.51

    Malignant melanoma of anal skin

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Malignant melanoma of anal margin
    • Malignant melanoma of perianal skin
    C43.51
    )
  • other and unspecified malignant neoplasm of anal margin (
    ICD-10-CM Diagnosis Code C44.500

    Unspecified malignant neoplasm of anal skin

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Unspecified malignant neoplasm of anal margin
    • Unspecified malignant neoplasm of perianal skin
    C44.500
    ,
    ICD-10-CM Diagnosis Code C44.510

    Basal cell carcinoma of anal skin

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Basal cell carcinoma of anal margin
    • Basal cell carcinoma of perianal skin
    C44.510
    ,
    ICD-10-CM Diagnosis Code C44.520

    Squamous cell carcinoma of anal skin

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Squamous cell carcinoma of anal margin
    • Squamous cell carcinoma of perianal skin
    C44.520
    ,
    ICD-10-CM Diagnosis Code C44.590

    Other specified malignant neoplasm of anal skin

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Other specified malignant neoplasm of anal margin
    • Other specified malignant neoplasm of perianal skin
    C44.590
    )
  • other and unspecified malignant neoplasm of anal skin (
    ICD-10-CM Diagnosis Code C44.500

    Unspecified malignant neoplasm of anal skin

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Unspecified malignant neoplasm of anal margin
    • Unspecified malignant neoplasm of perianal skin
    C44.500
    ,
    ICD-10-CM Diagnosis Code C44.510

    Basal cell carcinoma of anal skin

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Basal cell carcinoma of anal margin
    • Basal cell carcinoma of perianal skin
    C44.510
    ,
    ICD-10-CM Diagnosis Code C44.520

    Squamous cell carcinoma of anal skin

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Squamous cell carcinoma of anal margin
    • Squamous cell carcinoma of perianal skin
    C44.520
    ,
    ICD-10-CM Diagnosis Code C44.590

    Other specified malignant neoplasm of anal skin

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Other specified malignant neoplasm of anal margin
    • Other specified malignant neoplasm of perianal skin
    C44.590
    )
  • other and unspecified malignant neoplasm of perianal skin (
    ICD-10-CM Diagnosis Code C44.500

    Unspecified malignant neoplasm of anal skin

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Unspecified malignant neoplasm of anal margin
    • Unspecified malignant neoplasm of perianal skin
    C44.500
    ,
    ICD-10-CM Diagnosis Code C44.510

    Basal cell carcinoma of anal skin

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Basal cell carcinoma of anal margin
    • Basal cell carcinoma of perianal skin
    C44.510
    ,
    ICD-10-CM Diagnosis Code C44.520

    Squamous cell carcinoma of anal skin

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Squamous cell carcinoma of anal margin
    • Squamous cell carcinoma of perianal skin
    C44.520
    ,
    ICD-10-CM Diagnosis Code C44.590

    Other specified malignant neoplasm of anal skin

      2016 2017 2018 Billable/Specific Code
    Applicable To
    • Other specified malignant neoplasm of anal margin
    • Other specified malignant neoplasm of perianal skin
    C44.590
    )
The following code(s) above C21 contain annotation back-references
Annotation Back-References
In this context, annotation back-references refer to codes that contain:
  • Applicable To annotations, or
  • Code Also annotations, or
  • Code First annotations, or
  • Excludes1 annotations, or
  • Excludes2 annotations, or
  • Includes annotations, or
  • Note annotations, or
  • Use Additional annotations
that may be applicable to C21:
  • C00-D49
    2018 ICD-10-CM Range C00-D49

    Neoplasms

    Note
    • Functional activity
    • 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.
    • Morphology [Histology]
    • 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.
    • Primary malignant neoplasms overlapping site boundaries
    • 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.
    • Malignant neoplasm of ectopic tissue
    • 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).
    Neoplasms
  • C15-C26
    2018 ICD-10-CM Range C15-C26

    Malignant neoplasms of digestive organs

    Type 1 Excludes
    • Kaposi's sarcoma of gastrointestinal sites (C46.4)
    Type 2 Excludes
    • gastrointestinal stromal tumors (C49.A-)
    Malignant neoplasms of digestive organs
Code History
ICD-10-CM Codes Adjacent To C21
C18.2 Malignant neoplasm of ascending colon
C18.3 Malignant neoplasm of hepatic flexure
C18.4 Malignant neoplasm of transverse colon
C18.5 Malignant neoplasm of splenic flexure
C18.6 Malignant neoplasm of descending colon
C18.7 Malignant neoplasm of sigmoid colon
C18.8 Malignant neoplasm of overlapping sites of colon
C18.9 Malignant neoplasm of colon, unspecified
C19 Malignant neoplasm of rectosigmoid junction
C20 Malignant neoplasm of rectum
C21 Malignant neoplasm of anus and anal canal
C21.0 Malignant neoplasm of anus, unspecified
C21.1 Malignant neoplasm of anal canal
C21.2 Malignant neoplasm of cloacogenic zone
C21.8 Malignant neoplasm of overlapping sites of rectum, anus and anal canal
C22 Malignant neoplasm of liver and intrahepatic bile ducts
C22.0 Liver cell carcinoma
C22.1 Intrahepatic bile duct carcinoma
C22.2 Hepatoblastoma
C22.3 Angiosarcoma of liver
C22.4 Other sarcomas of liver

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.