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Small intestine

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Adenocarcinoma of the small intestine

Adenocarcinomas develop in the glandular cells (tissues) in the inner lining (mucosa) of the small intestine. Adenocarcinomas are the most common type of small intestine tumour. They account for about 30%–40% of all small intestine cancers.

About one-half of all small intestine adenocarcinomas develop in the duodenum (the first part of the small intestine closest to the stomach). The next most common site is the jejunum, followed by the ileum.

These tumours often grow and block (obstruct) the intestine.

Most people with adenocarcinoma are diagnosed with advanced disease, usually stage III or higher. At diagnosis, most people with adenocarcinoma will have cancer that has spread to the lymph nodes, liver or peritoneumperitoneumThe membrane that lines the walls of the abdomen and pelvis (parietal peritoneum), and covers and supports most of the abdominal organs (visceral peritoneum). (abdominal lining).


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