Skip to Content. This is the first page of Cancer. Use the menu to see other pages. Think of that menu as a roadmap for this entire guide. Anal cancer begins in the anus.
What you need to know about anal cancer
What Is Anal Cancer?
The anus is connected to the rectum by the anal canal. The anal verge is where the canal connects to the outside skin at the anus. The inner lining of the anal canal is the mucosa. Most anal cancers start from cells in the mucosa.
Anal cancer types
The abnormal growth of cells in the anus is called anal intraepithelial neoplasia AIN or anal squamous intraepithelial lesions SILs. Tumors that develop in or on the anus are either benign noncancerous or malignant cancerous. The different types of anal cancer , listed below, are based on the type of cells in which the cancer develops:. Squamous cell carcinoma begins in the outer lining of the anal canal. It is the most common type of anal cancer.
When cancer cells form into benign or malignant tumors in the tissues of the anus, anal cancer has occurred. The anus is the opening at the bottom of your intestines where stool exits the body. Anal cancer is rare, but when it occurs, it may spread to other parts of the body. Some noncancerous forms of anal cancer can also turn cancerous over time. If you have any of the below symptoms and risk factors, talk to your doctor about your concerns.