C21: Malignant neoplasm of anus and anal canal
C21.0: Malignant neoplasm: Anus, unspecified
The tissue in the body is made up of cells. With cancer, the cells multiply uncontrollably, which leads to a malignant neoplasm (abnormal growth of tissue) developing. The cancer cells can destroy the healthy tissue and spread throughout the body.
The anus is located at the end of the intestines and is ring-shaped. A sphincter muscle in the last segment of the intestines ensures that we only intentionally excrete feces through the anus.
You have cancer of the anus.
Please note: This ICD code may also derive from the ICD-O system. If this is the case, there are usually additional letters and numbers in addition to the code. It starts with the letter M, followed by 4 digits and then a slash. There is another digit after the slash.
If it is an ICD-O code, then this does not describe a malignant cancer in all cases. The last digit after the slash gives you more detailed information about this:
Patient Disclaimer
The information provided on this page is for general educational purposes only. It is not intended for self-diagnosis and does not replace professional medical advice. Always consult your doctor or a qualified healthcare provider with any questions or concerns about your health.
If you see an ICD diagnosis code (e.g., on a medical report), be aware that doctors may also include additional indicators to express diagnostic certainty. Only a healthcare professional can interpret these codes accurately in the context of your individual case.
For a complete understanding of your condition and what the diagnosis means for you, please speak directly with your doctor.