C15-C26: Malignant neoplasms of digestive organs

C21: Malignant neoplasm of anus and anal canal

Malignant neoplasm of the anus and anal canal refers to a group of health conditions characterized by the abnormal, uncontrolled growth of cells in the anus or the anal canal, the body's terminal portion of the digestive system. These diseases, collectively known as anal cancers, can be triggered by several factors, most commonly the Human Papillomavirus (HPV). Typical symptoms of malignant neoplasm of the anus and anal canal include bleeding, pain, itching in the anal area, changes in bowel movements, such as shape and consistency, and swollen lymph nodes in the anal or groin areas. In a disease's progression, the abnormal cell growth may spread, carrying the potential risk to damage other parts of the body. These conditions mainly affect the digestive system. The onset of the disease is usually slow, with symptoms taking time to manifest.