Valid for Submission
C21.0 is a billable diagnosis code used to specify a medical diagnosis of malignant neoplasm of anus, unspecified. The code C21.0 is valid during the fiscal year 2021 from October 01, 2020 through September 30, 2021 for the submission of HIPAA-covered transactions.
The ICD-10-CM code C21.0 might also be used to specify conditions or terms like adenocarcinoma of anus, anorectal adenocarcinoma, carcinoma of anus, malignant neoplasm of rectum, rectosigmoid junction and anus, malignant tumor of anus , malignant tumor of rectosigmoid junction, etc.
The following anatomical sites found in the Table of Neoplasms apply to this code given the correct histological behavior: Neoplasm, neoplastic anus, anal .
Unspecified diagnosis codes like C21.0 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.
Index to Diseases and Injuries
The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code C21.0 are found in the index:
The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:
- Adenocarcinoma of anus
- Anorectal adenocarcinoma
- Carcinoma of anus
- Malignant neoplasm of rectum, rectosigmoid junction and anus
- Malignant tumor of anus
- Malignant tumor of rectosigmoid junction
- Primary adenocarcinoma of anus
- Primary malignant neoplasm of anus
- Primary squamous cell carcinoma of anus
Diagnostic Related Groups - MS-DRG Mapping
Convert C21.0 to ICD-9 Code
Table of Neoplasms
The code C21.0 is included in the table of neoplasms by anatomical site. For each site there are six possible code numbers according to whether the neoplasm in question is malignant, benign, in situ, of uncertain behavior, or of unspecified nature. The description of the neoplasm will often indicate which of the six columns is appropriate.
Where such descriptors are not present, the remainder of the Index should be consulted where guidance is given to the appropriate column for each morphological (histological) variety listed. However, the guidance in the Index can be overridden if one of the descriptors mentioned above is present.
|»Neoplasm, neoplastic |
Information for Patients
The anus is where stool leaves your body when you go to the bathroom. It is made up of your outer layers of skin and the end of your large intestine. Anal cancer is a disease in which cancer cells form in the tissues of the anus.
Anal cancer is rare. It is more common in smokers and people over 50. You are also at higher risk if you have HPV, have anal sex, or have many sexual partners.
Symptoms include bleeding, pain, or lumps in the anal area. Anal itching and discharge can also be signs of anal cancer.
Doctors use tests that examine the anus to diagnose anal cancer. They include a physical exam, endoscopy, ultrasound, and biopsy.
Treatments include radiation therapy, chemotherapy, and surgery.
NIH: National Cancer Institute
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