There, they can form colony tumors. This process is called metastasis. These are cancers of the glandular cells that line the inside of the colon and rectum. The information given here refers to this type of cancer. Other, less common type of tumors may also develop in the colon and rectum.
Carcinoid tumors develop from hormone-producing cells of the intestine.
Gastrointestinal stromal tumors develop in the connective tissue and muscle layers in the wall of the colon and rectum. Lymphomas are cancers of immune system cells that typically develop in lymph nodes but may also start in the colon and rectum or other organs.