What is Small Intestine Cancer?

The small intestine is an organ in the digestive tract, located in between the stomach and the large intestine. The small intestine is about 15 to 20 feet long, and folds many times to fit into the abdomen. It is divided into three parts with the upper portion called the duodenum, the middle portion called the jejunum and the lower portion call the ileum. It's primary function is to help the body digest food and absorb nutrients, vitamins, and minerals from food.

Types of Small Intestine Cancer

There are four main types of small intestine cancer: adenocarcinoma, sarcoma, carcinoid tumors, and lymphoma.

• Carcinoid Tumor

  Carcinoid tumors are the most common type of small intestine cancer and represent a type of neuroendocrine tumor that starts in the hormone-producing cells of the small intestine. These tumors can cause excess production of certain hormones, leading to additional symptoms and complications. Carcinoid tumors usually begin in the ileum, or the final section of the small intestine.

• Adenocarcinoma

  Adenocarcinoma is the 2nd most common type of small intestine cancer and accounts for about 35% of diagnoses. These tumors start in the cells lining the inside of the small intestine. Adenocarcinomas often start as a small benign growth called a polyp, which eventually turns into cancer. Most adenocarcinomas of the small intestine start in the duodenum, or the first 8 inches of the small intestine closest to the stomach.

• Sarcoma

  Sarcomas start in the connective tissues that support and surround the body's internal organs and structures. There are different types of sarcomas that may form in the small intestine. Leiomyosarcoma is a type of sarcoma that arises from smooth muscle tissue in the wall of the small intestine. Gastrointestinal stromal tumors (GISTs) are another type of sarcoma that develop in cells called interstitial cells of Cajal (ICC). These cells control the muscles of the GI tract and indirectly help you digest food. GISTs may occur anywhere in the small intestine.

• Lymphoma

  Lymphomas start in the lymphoid tissue of the small intestine. Lymphomas of the small intestine are usually non-Hodgkin lymphomas, which develop in B- or T-cell lymphocytes that help protect the body from germs, viruses, and infections. Lymphomas of the small intestine most commonly form in the jejunum or ileum.