MDCT and MRI of the ampulla of Vater (part II): non-epithelial neoplasms, benign ampullary disorders, and pitfalls

Abstract

The purpose of this two-part article is to review the cross-sectional imaging features of benign and malignant ampullary conditions with endoscopic and histopathologic correlation and to present the most common pitfalls in the evaluation of the ampulla. In this part, we will review the mesenchymal and secondary neoplasms of the ampulla, a vast array of benign ampullary conditions, causes of bulging papilla, and pitfalls. Familiarity with ampullary pathologic conditions and pitfalls, as well as the use of optimized MDCT and MRI techniques, may improve the diagnostic accuracy of radiologists facing ampullary abnormalities.

Imaging of Ampullary and Periampullary Conditions

“…The incidence increases with age and the reported incidence is highly variable, depending on the imaging type and the population, and ranges from 1 to 30%. 32,33 The majority of periampullary diverticula are incidentally found and are asymptomatic, but occasionally can cause complications. Nonbiliopancreatic complications include diverticulitis, hemorrhage, perforation or fistula formation.…”

“…2) and may appear as susceptibility artifact on MRI. Multiplanar reconstructions and oral contrast can improve the diagnostic yield of CT. 32 At times, a small fluid filled diverticulum can be difficult to differentiate from an ampullary mass or cyst on imaging.…”

“…Prevalence of SOD has been reported to be up to 15% in the general population. 32 Gold standard for diagnosis of SOD is manometric demonstration of sphincter pressures >40 mm Hg during ERCP. Endoscopic manometry is, however, an invasive procedure.…”

“…Like other neuroendocrine tumors in the bowel or the pancreas, ampullary carcinoid tumors (and their locoregional lymph node metastases) are isointense to muscle on T1-weighted images and are either hyper-or isointense to muscle on T2-weighted images 8,68 The most characteristic appearance of carcinoid tumor of the ampulla of Vater is an avidly enhancing discrete submucosal mass without necrosis or hemorrhage 32,72 (►Fig. 14).…”

“…53 MR findings of an ampullary mass, papillary bulging, and irregular CBD stricture are associated with cancer. 32…”