Ampullary adenocarcinoma is a rare malignant neoplasm arising from the ampulla of Vater, comprising 6-20% of periampullary cancers. Because it produces biliary obstruction symptoms early, it is diagnosed earlier than other periampullary tumors and has better prognosis (5-year survival 30-70%). 'Double duct sign' — simultaneous dilatation of both CBD and pancreatic duct — is the most characteristic imaging finding. Endoscopic evaluation (ERCP + biopsy) is the gold standard for diagnosis. Whipple procedure (pancreaticoduodenectomy) is curative treatment.
Age Range
50-80
Peak Age
65
Gender
Equal
Prevalence
Rare
Ampullary adenocarcinoma arises from intestinal or pancreatobiliary-type epithelium in the ampulla of Vater. It follows the adenoma-carcinoma sequence — progressing from adenomatous polyps through dysplasia to carcinoma (APC/beta-catenin pathway). Due to the anatomic location of the ampulla, even small tumors can obstruct the CBD and pancreatic duct orifice causing early obstructive jaundice — this early symptom allows diagnosis at a curative stage. As the tumor grows, it invades the duodenal wall, pancreatic head, and periampullary tissues. In imaging, double duct sign (simultaneous CBD + pancreatic duct dilatation) results from the tumor obstructing both duct orifices. Ampullary tumors may show papillary or ulcerative growth pattern — papillary type has better prognosis.
Simultaneous dilatation of CBD and pancreatic duct — resulting from a lesion at the ampulla of Vater obstructing the common exit of both ducts. Most characteristic imaging finding for ampullary adenocarcinoma, pancreatic head carcinoma, or distal cholangiocarcinoma.
Simultaneous dilatation of both CBD (>6 mm) and pancreatic duct (>3 mm) on portal venous phase — double duct sign. A small enhancing mass may be identified at the ampullary region at the lower end of dilatation. Pancreatic head is normal sized or mildly enlarged. Gallbladder may be distended (Courvoisier sign). Intrahepatic bile duct dilatation also accompanies. Tumor is usually small (<3 cm) and does not form a large mass like pancreatic adenocarcinoma.
Report Sentence
Simultaneous dilatation of CBD and pancreatic duct (double duct sign) with a small enhancing mass in the ampullary region is noted; ampullary neoplasm should be primarily considered.
Mass with intermediate signal intensity in ampullary region at the lower end of dilated CBD and pancreatic duct on T2-weighted images and MRCP. Abrupt termination ('meniscus sign') at distal end of both ducts seen on MRCP. Tumor may protrude into duodenal lumen — seen as intraluminal polypoid structure on T2. Periampullary fat planes are evaluated — if invasion is present, fat signal loss is seen on T2.
Report Sentence
Simultaneous CBD and pancreatic duct dilatation with abrupt termination (meniscus sign) and small mass at ampullary region on MRCP; consistent with ampullary neoplasm.
Hypervascular enhancing small lesion in ampullary region on arterial phase — more prominent in intestinal-type ampullary adenocarcinoma. Lesion may invade duodenal wall and is evaluated together with duodenal mucosal enhancement. Pancreatobiliary type enhances less and may show hypovascular pattern similar to pancreatic head adenocarcinoma. Arterial phase is also critical for evaluating vascular anatomy (SMA, celiac) and tumor-vessel relationship.
Report Sentence
Hypervascular enhancing small lesion at ampullary region on arterial phase is noted, consistent with ampullary neoplasm.
CBD dilatation (>6 mm) and distended gallbladder (Courvoisier sign) on US — suggests periampullary obstruction with painless jaundice. Ampullary lesion may not be directly visualized on US — due to duodenal gas artifact. Intrahepatic bile duct dilatation is also seen. Pancreatic duct dilatation may not always be demonstrated on transabdominal US. Differentiation of obstructive cause at lower CBD (stone vs mass) should be made — posterior acoustic shadow expected with stone, solid hypoechoic structure with mass.
Report Sentence
CBD dilatation and distended gallbladder (Courvoisier sign) are noted, consistent with distal biliary obstruction; ampullary region should be evaluated with CT/MR.
Mass showing diffusion restriction in ampullary region on DWI — bright signal at high b-value, low value on ADC map. Malignant ampullary lesions show diffusion restriction due to high cellular density. ADC values are lower than benign adenoma — ADC threshold is helpful in malignant-benign differentiation (malignant typically <1.2 × 10⁻³ mm²/s). Surrounding duodenal mucosa and pancreas parenchyma are used as reference.
Report Sentence
Lesion showing diffusion restriction in ampullary region on DWI is noted and should be evaluated for malignancy.
Criteria
Intestinal epithelium origin; CK20+, CDX2+, MUC2+
Distinct Features
More hypervascular enhancement, papillary growth, better prognosis (60-70% 5-year survival)
Criteria
Pancreatobiliary epithelium origin; CK7+, MUC1+, CDX2-
Distinct Features
Less vascular enhancement, infiltrative growth, worse prognosis (20-40% 5-year survival)
Criteria
Coexistence of both histologic components
Distinct Features
Intermediate prognosis; dominant component determines treatment response
Distinguishing Feature
Distal cholangiocarcinoma forms thickening/mass at CBD wall, pancreatic duct usually normal; ampullary tumor causes simultaneous dilatation of both ducts
Distinguishing Feature
Choledocholithiasis shows filling defect + posterior acoustic shadow on MRCP with single duct dilatation; ampullary tumor has solid mass + double duct dilatation
Distinguishing Feature
Ampullary adenoma is smaller, homogeneously enhancing polypoid lesion with less diffusion restriction on DWI (higher ADC); adenocarcinoma has invasion and prominent diffusion restriction
Distinguishing Feature
Acute cholangitis presents acutely with fever + leukocytosis and duct wall enhancement; ampullary tumor presents with painless jaundice and solid mass at ampulla
Urgency
urgentManagement
surgicalBiopsy
NeededFollow-up
specialist-referralCurative treatment for ampullary adenocarcinoma is Whipple procedure (pancreaticoduodenectomy). Endoscopic biopsy via ERCP is gold standard for diagnosis. Local papillectomy may be sufficient for T1 (ampulla-limited) tumors. Neoadjuvant chemotherapy is controversial. 5-year survival is 80-90% for Tis/T1, 50-60% for T2, 20-30% for T3-4. It has the best prognosis among periampullary tumors.
Ampullary adenocarcinoma has the best prognosis among periampullary region tumors (5-year survival 40-60%). Whipple procedure (pancreatoduodenectomy) is the curative surgery. EUS and ERCP with biopsy are the most valuable methods for early diagnosis.