Malignant tumours of the small intestine.

Adenocarcinoma, neuroendocrine tumours, sarcomas and lymphomas are the four most common malignant tumours arising in the small intestine, although over forty different histological subtypes are described. Collectively these account for only 2% of cancers of the digestive system. The incidence of small bowel cancer has increased in recent decades with a four-fold increase in carcinoid tumours. Risk factors for small bowel tumours include coeliac disease, inflammatory bowel disease and a number of genetic abnormalities. The non-specific nature of their symptoms and the difficulty in visualising these tumours with normal endoscopic techniques often results in late diagnosis. Furthermore the paucity of literature on this topic has made it difficult to standardise management. There has however been marked improvement in imaging methods resulting in earlier diagnosis in many cases. As expected, early detection of localised, well differentiated tumours followed by surgical resection with negative margins offers the best chance of long term survival. Better adjuvant treatment, notably for gastrointestinal stromal tumours, has improved 5-year survival rates significantly. Development of surveillance guidelines for at risk populations may be a valuable way of improving early diagnosis of this challenging group of conditions.