Nonampullary duodenal adenoma: Current understanding of its diagnosis, pathogenesis, and clinical management

Abstract

Nonampullary duodenal adenomas are relatively common in familial adenomatous polyposis (FAP), but nonampullary sporadic duodenal adenomas (SDAs) are rare. Emerging evidence shows that duodenal adenomas, regardless of their anatomic location and whether they are sporadic or FAP-related, share morphologic and molecular features with colorectal adenomas. The available data suggest that duodenal adenomas develop to duodenal adenocarcinomas via similar mechanisms. The optimal approach for management of duodenal adenomas remains to be determined. The techniques for endoscopic resection of duodenal adenoma include snare polypectomy, endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and argon plasma coagulation ablation. EMR may facilitate removal of large duodenal polyps. Although several studies have reported cases of successful ESD for duodenal adenomas, the procedure is technically difficult to perform safely because of the anatomical properties of the duodenum. Although current clinical practice recommends endoscopic resection of all large duodenal adenomas in patients with FAP, endoscopic treatment is usually insufficient to guarantee a polyp-free duodenum. Surgery is indicated for FAP patients with severe polyposis or nonampullary SDAs or FAP-related polyps not amenable to endoscopic resection. Further studies are needed to develop newer endoscopic techniques to guide diagnostic and therapeutic decisions for future management of nonampullary duodenal adenomas.

Keywords: Duodenal adenoma; Endoscopic mucosal resection; Endoscopic submucosal dissection; Endoscopy; Familial adenomatous polyposis.

Figure 1

Snare polypectomy. A: A approximately 10 mm peduculated adenoma in the second portion of the duodenum; B: Snare polypectomy procedure.

Figure 2

Endoscopic mucosal resection. A: An approximately 20 mm polypoid mass in the second portion of the duodenum; B: Injection of submucosal saline solution with indigocarmine; C: Endoscopic mucosal resection (EMR) procedure; D: A clear, post-EMR ulcer.

Figure 3

Endoscopic submucosal dissection. A: A 12 mm sized superficial elevated type (IIa) lesion in the second portion of the duodenum; B: Circumferential mucosal incision and submucosal dissedtion; C: The lesion successfully removed en bloc without complications; D: A 27 mm resected specimen with adenoma.