Malignant Anal Tumors

These are cancerous tumors. There are a number of different types, most of which are described in the list below. Other types of malignant anal tumors are very rare.

Squamous cell skin cancer

This is the most common type of tumor. This type of anal cancer begins in the cells that line the anal margin and most of the anal canal. Learn more about squamous cell skin cancer.

Cloacogenic carcinomas (also called transitional cell carcinomas)

These make up most of the remainder of anal cancers. This cancer type affects the cloaca, the bottom part of the large intestine that stores the stool.  

Adenocarcinomas

These account for a small number of cases of anal cancer, and affect the anal glands. Paget's Disease (not the same as the Paget's bone disease or Paget's disease of the breast) is a type of adenocarcinoma.

Basal cell carcinoma and melanoma

These are types of skin cancers that can rarely cause anal cancer. Learn more about basal cell carcinoma and melanoma.