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Small intestine

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What is small intestine cancer?

Small intestine cancer is a malignant tumour that starts in cells of the small intestine. Malignant means that it can spread, or metastasize, to other parts of the body.

The small intestine, or small bowel, is part of the digestive system. It is a hollow, tube-like organ in the abdomen. The small intestine is made up of the duodenum, jejunum and ileum. The duodenum receives partially digested food from the stomach. Digestive juices and bile are added to the food in the duodenum, and then the food is passed to the jejunum. The jejunum breaks the food down more, absorbs nutrients and passes digested food to ileum. The ileum absorbs nutrients and passes what is left on to the large intestine.

Cells in the small intestine sometimes change and no longer grow or behave normally. These changes can cause precancerous conditions. This means that the cells are not yet cancer but there is a higher chance these abnormal changes will become cancer. The most common precancerous condition of the small intestine is adenomatous polyps, or adenomas.

In some cases, changes to cells in the small intestine can cause cancer. Most often, small intestine cancer starts in gland cells in the lining of the small intestine. This type of cancer is called adenocarcinoma of the small intestine. The second most common type of small intestine cancer starts in neuroendocrine cells and is called a neuroendocrine tumour.

Other types of cancer can also start in the small intestine, but they are less common. Lymphoma is a type of cancer that starts in lymph tissue of the small intestine. Sarcoma is a type of cancer that can start in the wall of the small intestine.

Diagram of the digestive system


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