D01.3: Carcinoma in situ: Anus and anal canal

The tissue in the body is made up of cells. Cancer causes the cells to change, resulting in them multiplying uncontrollably. This leads to a malignant neoplasm (abnormal growth of tissue) developing. This abnormal and excessive tissue growth is called cancer. In your case, the cancer is limited to the skin or mucous membranes. This means that the cancer is very superficial and has not currently extended beyond a certain limit in the tissue. This also means the cancer has not yet been able to spread to other organs. However, the cancer cells can destroy the healthy tissue.

You often don’t get any symptoms with this early form of cancer.

You have an early form of cancer in the inner lining (mucous membrane) of your anal canal or anus. The last segment of the large intestine consists of 2 sections. These 2 sections are the rectum and anal canal. The feces are collected in the rectum. The feces then move through the short anal canal to the anus. Feces are excreted through the anus. 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.