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NONAMPULLARY DUODENAL ADENOMAS

Adenomas of the duodenum that do not involve the major duodenal papilla can occur sporadically or in the context of genetic syndromes such as FAP or Peutz-Jeghers syndrome and have the potential to undergo malignant transformation to duodenal cancer. Management of patients with FAP, Peutz-Jeghers syndrome, and other related conditions is discussed in another guideline. The remainder of this guideline will focus on the management of sporadic duodenal adenomas.

Evaluation of nonampullary duodenal lesions before endoscopic therapy

The endoscopic appearance of duodenal adenomas may be indistinguishable from nonadenomatous polyps such as Brunner's gland tumors, inflammatory polyps, carcinoid tumors, and hamartomas. Suspicious lesions should be biopsied before attempted endoscopic resection. Before endoscopic resection of a duodenal polyp, it is important to ensure that the polyp does not involve the ampulla because the pancreaticobiliary systems need to be addressed as discussed above. Examination with a side-viewing endoscope or EUS can be helpful in making this distinction.

Role of EUS. The precise role of EUS in the management of duodenal adenomas is unclear. EUS can establish the relationship of the lesion to the pancreaticobiliary tree when this is uncertain after forward and side-viewing examinations and can obviate the need for ERCP. EUS can also allow determination of endoscopic resectability when biopsy specimens have shown high-grade dysplasia and endoscopic findings are suspicious for malignancy, and it may be useful for evaluation of polyps larger than 2 cm.

Endoscopic resection techniques

Techniques of endoscopic removal of duodenal adenomas are not standardized, although the general approach is similar to that of colonic polyps, particularly those of the right colon because of the thinness of the duodenal wall. A submucosal injection to create a submucosal fluid cushion may be useful for removal of flat polyps. The lack of lifting during injection suggests underlying malignancy, as previously mentioned. Endoscopic mucosal resection techniques have also been described in the removal of duodenal lesions. Adjuvant ablative therapies such as the use of argon plasma coagulation or electrocoagulation may be used to destroy residual or recurrent adenomatous tissue not removed during attempts at primary snare resection. Small or flat lesions may sometimes be completely removed with ablative methods alone such as argon plasma coagulation, neodymium:yttrium-aluminum-garnet laser, or electrocautery.

Results of endoscopic resection for sporadic duodenal adenoma

Data on the clinical success of resection of duodenal adenoma in patients with sporadic polyps are based on a few small case series. In one series of 21 patients with lesions of a median size of 27.5 mm (range 8-50 mm), the success rate for endoscopic removal after a 3-month interval was 55%. After a median follow-up period of 71 months, local recurrences developed in 25%, which were re-treated endoscopically. No patients had carcinoma during the follow-up period.

Generally, larger lesions are more difficult to remove, and lesions with greater than 33% circumferential involvement of the lumen should be considered for surgical resection. Complications after endoscopic resection of duodenal adenomas are similar in nature to complications of colonoscopic polypectomy and include perforation, bleeding, and complications related to sedation.

Surveillance for residual or recurrent neoplastic tissue

It is recommended that all patients who have undergone endoscopic resection of duodenal adenomas be considered for surveillance endoscopy for the detection and treatment of recurrence. On the basis of limited data, formal recommendations cannot be given regarding surveillance intervals and should be applied on an individual basis based on the adequacy of resection, degree of dysplasia, and underlying comorbid medical illnesses. End points for surveillance have not been established.

Impact of duodenal and ampullary adenomas on colorectal cancer screening

Published data suggest that patients with sporadic ampullary or duodenal neoplasia are at higher risk for the development of colorectal neoplasia. Until more definitive data are available, it is reasonable to offer screening colonoscopy to all patients who have duodenal or ampullary adenomas.

SUMMARY

Ampullary and duodenal adenomas have the potential for malignant transformation and require appropriate diagnostic evaluation. (1C)

Both ERCP and EUS are important tools in the evaluation and staging of ampullary adenomas and can assist in selecting candidates for endoscopic or surgical therapy. (1C)

Techniques of endoscopic removal of ampullary neoplasms are not standardized and should be performed by experienced endoscopists. (2C)

Patients undergoing endoscopic removal of ampullary and duodenal neoplasms should undergo postprocedure surveillance to ensure complete tissue removal and lack of disease recurrence. (2C)

d Endoscopy is useful for evaluation and resection of sporadic duodenal adenomas using techniques similar to those used during polypectomy. (2C)

d Patients with sporadic ampullary or duodenal adenomas are at increased risk for colon polyps and should be offered screening colonoscopy. (2C)

REFERENCES(Ellipsis)


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