Treatment of nonampullary sporadic duodenal adenomas with endoscopic mucosal resection or ablation.

Malignant neoplasms of the small intestine are rare; US annual incidence and mortality are 8,810 and 1,170, respectively [1]. Duodenal adenocarcinoma is even rarer, accounting for \0.5 % of all gastrointestinal malignancies but up to *60 % of all small bowel cancers [2]. One proposed mechanism of duodenal carcinogenesis invokes the adenoma–carcinoma sequence, analogous to colorectal adenocarcinoma. Duodenal adenomas, regarded as potential premalignant lesions, are prevalent among patients with familial adenomatous polyposis, but sporadic adenomas among the general population are uncommon [3]. Given concern over malignant transformation, the traditional standard of care has been radical surgical excision. Nevertheless, surgery is associated with significant perioperative mortality and morbidity, lengthy hospital courses, and long-term complications, which diminish the quality and quantity of life [4]. Endoscopic intervention is a promising alternative therapeutic option. Duodenal adenomas are classified as either ampullary (adenomas of the major duodenal papilla) or non-ampullary. Successful endoscopic treatment of conventional ampullary adenomas and wide excision of laterally spreading ampullary adenomas is well-described [5]. Endoscopic management of non-ampullary adenomas has been reported, although data are sparse in comparison with those for ampullary adenomas. Notably, many duodenal adenomas can exist for years, particularly in familial polyposis patients, without malignant transformation. Recent data from Okada et al. [6] reveal that non-ampullary sporadic duodenal adenomas (NSDAs) with low-grade dysplasia progress infrequently to adenocarcinoma, although with some risk of progression to high-grade dysplasia, warranting surveillance biopsies at 6–12 months. Highgrade dysplasia lesions and large NSDAs ([2 cm) more often progress to adenocarcinoma, warranting immediate intervention. Endoscopic intervention in the duodenum is associated with a higher risk of complications than intervention elsewhere in the gastrointestinal tract. Perforation of the relatively thin duodenal wall is a particular concern. Perforations can be difficult to manage, and contribute to patient morbidity and mortality, average length of stay, and healthcare cost. Polypectomy in the duodenum also carries a higher risk of bleeding than in the colon; this is likely to be associated with the rich vascular supply of the proximal small intestine [4]. Duodenal polypectomy can also cause pancreatitis, particularly when the adenoma involves the major papilla, necessitating endoscopic ampullectomy [7]. Sepsis from endoscopic ampullectomy has also been reported [8]. The therapeutic techniques used to treat duodenal adenomas encompass several endoscopic modalities, including polypectomy, endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and ablation (e.g. argon plasma coagulation). ESD involves en-bloc resection with clear margins but is, unfortunately, timeconsuming, technically difficult, and associated with a high risk of perforation [9]. R. Perumpail Department of Medicine, Stanford University, Stanford, CA, USA