Intermediate

There are four types of benign small bowel tumours that have a strong tendency for malignant change. Each shows a spectrum of activity from truly benign to frank cancer. They include:

• villous adenoma:
  • closely associated with carcinoma
  • small bowel polyps may accompany up to half of all cases of Gardner's syndrome
• smooth muscle tumours:
  • may present with haemorrhage, obstructive symptoms or a palpable mass
  • treated by wide resection and occasionally respond to chemotherapy
• duodenal apudomas:
  • 10% of all gastrinomas arise at this site
  • treated by local excision or pancreatoduodenectomy
• carcinoid tumours:
  • the ileum is the second most frequent site of occurrence
  • approximately one third have metastasized by the time of diagnosis