Insulinoma in a Patient With Annular Pancreas

Abstract

Intraoperative ultrasonography has facilitated the localization of insulinomas. In this report, we describe a patient who was found to have an insulinoma in association with an annular pancreas. Because such tumors can be in close approximation to major pancreatic ductal structures, intraoperative ultrasonography can be useful for not only localizing the lesion but also delineating the related anatomic features. Although the optimal management of an asymptomatic annular pancreas has not been determined, our patient had no evidence of chronic pancreatitis and no narrowing of the duodenal lumen; therefore, no bowel bypass procedure was done.

The Epidemiology of Annular Pancreas in the United States

“…The mechanism of pancreatitis is unclear in patients with annular pancreas, probably through an obstructive mechanism 7. In rare instances, as reported in few case reports, annular pancreas can be complicated with development of pancreatic cyst or pancreatic cancer as found in our cohort of patients 39–49. This has previously been attributed to chronic inflammatory changes in this area associated with pancreatitis 7.…”

“…7 In rare instances, as reported in few case reports, annular pancreas can be complicated with development of pancreatic cyst or pancreatic cancer as found in our cohort of patients. [39][40][41][42][43][44][45][46][47][48][49] This has previously been attributed to chronic inflammatory changes in this area associated with pancreatitis. 7 Other common disease associations included gastritis, duodenitis, GI bleeding, H. pylori infection, and GI obstruction.…”

An annular pancreas associated with carcinoma of the papilla of Vater: report of a case

“…In the surgical cases of annular pancreas reviewed by Yogi et al [14], 9 (8.5%) of the 106 cases displayed a pancreaticobiliary malignancy (5 ampullary carcinomas, 2 pancreatic carcinomas, and 2 cholangiocarcinomas). Among the cases reported in the English literature, the most common pancreaticobiliary neoplasia associated with an annular pancreas was ampullary carcinoma (6 cases) ( Table 1) [15][16][17][18][19], followed by pancreatic carcinoma (5 cases) [20][21][22][23][24], cholangiocarcinoma (2 cases) [12,25], insulinoma (1 case) [26], and mucinous cystic neoplasm (MCN) (1 case) [27]. The chronic obstruction caused by an annular pancreas has been postulated to prompt continuous exfoliation of cells in the region of the ampulla and rapid mucosal turnover, facilitating dysplastic changes and metaplasia in that region [17].…”