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This is one of a series of statements discussing the use of gastrointestinal endoscopy in common clinical situations. The Standards of Practice Committee of the American Society for Gastrointestinal Endoscopy prepared this text. In preparing this guideline, MEDLINE and PubMed databases were used to search publications through the last 15 years related to ampullary and duodenal adenomas by using the keyword(s) "ampullary adenoma" and each of the following: "ampullectomy," "duodenal adenoma," and "familial adenomatous polyposis." The search was supplemented by accessing the "related articles" feature of PubMed with articles identified on MEDLINE and PubMed as the references. Pertinent studies published in English were reviewed. Studies or reports that described fewer than 10 patients were excluded from analysis if multiple series with greater than 10 patients addressing the same issue were available. Recommendations were made on the basis of the reviewed studies and were graded as to the strength of the supporting evidence (Table 1).

Guidelines for appropriate use of endoscopy are based on a critical review of the available data and expert consensus. Further controlled clinical studies may be needed to clarify aspects of this statement, and revision may be necessary as new data appear. Clinical consideration may justify a course of action at variance to these recommendations.

TABLE 1. Grades of recommendation*

Grade of recommendation	Clarity of benefit	Methodologic strength of supporting evidence	Implications
1A	Clear	Randomized trials without important limitations	Strong recommendation; can be applied to most clinical settings
1B	Clear	Randomized trials with important limitations (inconsistent results, nonfatal methodologic flaws)	Strong recommendation; likely to apply to most practice settings
1Cþ	Clear	Overwhelming evidence from observational studies	Strong recommendation; can apply to most practice settings in most situations
1C	Clear	Observational studies	Intermediate-strength recommendation; may change when stronger evidence is available
2A	Unclear	Randomized trials without important limitations	Intermediate-strength recommendation; best action maydiffer depending on circumstances or patients’ or societal values
2B	Unclear	Randomized trials with important limitations (inconsistent results, nonfatal methodologic flaws)	Weak recommendation; alternative approaches may be better under some circumstances
2C	Unclear	Observational studies	Very weak recommendation; alternative approaches likely to be better under some circumstances
3	Unclear	Expert opinion only	Weak recommendation; likely to change as data become available

*Adapted from Guyatt G, Sinclair J, Cook D, et al. Moving from evidence to action. Grading recommendationsda qualitative approach. In: Guyatt G, Rennie D,
editors: Users’ guides to the medical literature. Chicago: AMA Press; 2002. p. 599-608.

AMPULLARY ADENOMAS

Adenomas of the major duodenal papilla, also known as ampullary adenomas, can occur sporadically or in the context of genetic syndromes such as familial adenomatous polyposis (FAP). These lesions have the potential to undergo malignant transformation to ampullary cancer. Ampullary adenomas have historically been treated surgically. Surgical options include pancreaticoduodenectomy (Whipple's procedure) or transduodenal ampullectomy (which can occasionally leave behind residual adenomatous tissue). Surgical management often allows complete removal but carries morbidity, including anastomotic dehiscence and fistulae in 9% and 14% of patients, respectively, and mortality rates ranging from 1% to 9%, although complication rates tend to be related to surgical case volume.

Endoscopic approaches for the evaluation and treatment of ampullary adenomas now represent a viable alternative to surgical therapy.

Evaluation of ampullary lesions before endoscopic therapy

Ampullary adenomas cannot always be distinguished from ampullary carcinomas or nonadenomatous polyps (carcinoid tumors, gangliocytic paragangliomas, etc) on the basis of endoscopic appearance alone. Suspicious ampullary lesions should be biopsied before endoscopic resection is attempted. Brush cytology may offer additional information to biopsy for the detection of malignancy in selected cases.

There is no consensus on which ampullary adenomas should be kept under surveillance and which lesions should be removed endoscopically or surgically. An incidental, small ampullary adenoma may not require further evaluation or therapy, depending on the clinical context. Lesions with high-grade dysplasia often warrant therapy because they may harbor malignancy missed on biopsy and to prevent progression to malignancy.

Several authors have advocated that endoscopic resection should only be performed in patients without evidence of invasive cancer. Although endoscopic removal of ampullary adenocarcinoma has been described, it cannot be endorsed for routine management. The finding of high-grade dysplasia is not a contraindication to endoscopic removal, but it should prompt removal of the lesion by either endoscopic or surgical means rather than management by surveillance on the basis of health status.

There are no definitive guidelines as to the size or diameter above which endoscopic removal of ampullary adenomas should not be attempted. Many authors recommend that lesions R4 to 5 cm not be treated endoscopically, although there are reports of successful endoscopic resection of ampullary lesions of greater size. The size of the lesion, however, can affect the endoscopic approach to resection, as discussed below.

Endoscopic features such as firmness, ulceration, nonlifting with attempted submucosal injection to createa submucosal fluid cushion, and friability suggest possible malignancy and such lesions should be considered for surgical resection even in the absence of malignancy on biopsy specimens.

Role of endoscopic retrograde cholangiopancrea tography and endoscopic ultrasound. ERCP and EUS provide useful information in the assessment of ampullary adenomas. EUS and intraductal US (IDUS) have emerged as useful techniques to assess the depth of involvement in patients with ampullary neoplasms. These modalities allow the assessment and extent of intraductal extension and extension beyond the muscularis propria and can allow evaluation of periampullary lymph nodes in those patients suspected of having cancer. EUS or IDUS of lesions that appear suspicious for harboring cancer may help to select which patients can be considered candidates for endoscopic versus surgical therapy and for guiding the surgical therapy. EUS has been shown to be superior to CT, magnetic resonance imaging, or transabdominal ultrasonography for tumor staging. Magnetic resonance imaging has been found to be superior to EUS for nodal staging in this setting, whereas CT scans and positron emission tomographic scans can detect metastases not seen on EUS or IDUS. One prospective study comparing EUS, IDUS, and CT scan favored IDUS as the most accurate imaging study with an accuracy superior to that of EUS.

There is disagreement as to whether all patients with ampullary adenomas should undergo EUS before therapy, with some experts proposing that lesions less than 1 cm in diameter or those that do not have suspicious signs of malignancy (ulceration, induration, bleeding) do not require ultrasonographic evaluation before endoscopic removal. If available, EUS examination should be considered before endoscopic or surgical resection is performed.

ERCP with both biliary and pancreatic duct evaluation should be performed at the time of endoscopic resection to assess for evidence of extension into either ductal system. Several authors have used evidence of intraductal extension as a criterion for surgical referral. Other investigators have shown that less than 1 cm of extension into the common bile duct or pancreatic duct does not preclude endoscopic therapy because tissue invading to this level may be endoscopically exposed and ablated.