Editing Small bowel benign tumours (section)

== '''Adenoma''' ==

* Most common 
* Appear to be more common in ileum (50%) than duodenum (20%) or jejunum (30%)
* Pathophysiology
** See 'adenocarcinoma' page for the adenoma-carcinoma sequence
* Classification
** Villous
*** High risk of malignant transformation (up to 50%)
*** Coincident colonic adenomas are common
*** Often present with bleeding or obstruction
*** Can be associated with FAP
** Tubular
*** Lower malignant potential
*** More common in duodenum
*** Usually asymptomatic
** Brunner's gland adenomas
*** Rare
*** Caused by hyperplasia of the exocrine glands within the proximal duodenal mucosa
*** Can produce symptoms mimicking PUD
*** No malignant potential - don't perform radical resection
*** Symptomatic lesions can be resected endoscopically or surgically
* Presentation
** Mostly asymptomatic, occurring singly and found at autopsy
* Management
** Sporadic duodenal adenomas
*** If possible, remove endoscopically unless >4cm, and screen for CRC
*** Need to weigh up risk of malignancy carefully if surgery would be required - EUS can help
*** EMR has a good success rate (but high risk of complications including bleeding, recurrence and perforation)
*** If it recurs after endoscopic resection or continues to change, pancreaticoduodenectomy will be required
** Surgically remove jejunal/ileal adenomas
** Familial adenomas in FAP
*** Found in 50-90%, with 5% lifetime risk of adenocarcinoma
*** Use Spigelman classification to direct management
*** Biopsy of all suspicious, villous or >3cm adenomas in addition to random duodenal biopsy specimens
*** High-grade dysplasia, carcinoma in situ, or Spigelman stage IV necessitates pancreaticoduodenectomy/pancreas-preserving duodenectomy
***

*