C21: Malignant neoplasm of anus and anal canal
C21.2: Malignant neoplasm: Cloacogenic zone
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.
A “cloaca” is where the intestinal and urinary tracts join together in one unit. In human development, everyone has a cloaca. Normal development involves a wall forming between the intestinal and urinary tracts. For some people, a cloaca or residual tissue from the cloaca remains present.
In your case, cancer has developed from this tissue.
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.