eMedicine Specialties > Oncology > Carcinomas of the Gastrointestinal Tract

Carcinoma of the Ampulla of Vater: Differential Diagnoses & Workup

Author: Nafisa K Kuwajerwala, MD, Staff Surgeon, Breast Oncology, William Beaumont Hospital
Coauthor(s): Pankaj Chaturvedi, MBBS, MS, Associate Professor, Head and Neck Surgery, Department of Surgical Oncology, Tata Memorial Hospital, India; Ronald S Chamberlain, MD, Chairman, Chief, Department of Surgery, Saint Barnabas Medical Center; Venkata Subramanian Kanthimathinathan, MD, Staff Physician, Department of General Surgery, Loma Linda University Medical Center; Uma Chaturvedi, MD, MBBS, DPB, Lecturer, Department of Pathology, KJ Somaiya Hospital and Research Center, India; Gunateet Goswami, MD, Consulting Staff, Internal Medicine Associates, Mount Clemens, Michigan; Consulting Staff, Department of Cardiology, Henry Ford Hospital
Contributor Information and Disclosures

Updated: Apr 8, 2009

Differential Diagnoses

Other Problems to Be Considered

Duodenal carcinoma
Adenoma at the ampulla of Vater

Workup

Laboratory Studies

• Blood biochemistry
  • Test for anemia caused by bleeding from the ampullary mass.
  • Test for hyperbilirubinemia (conjugated type) due to blockage of the biliary outflow.
  • Test for a rise in alkaline phosphatase level, again due to blockage.
  • Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) rise in long-standing obstruction.
  • Fecal occult blood testing results may be positive in ulcerated or bleeding tumors.
  • In cases with complete obstruction and bleeding, the stool may be pale or silver white, so-called silver stools.
  • A rise in serum amylase is not uncommon.
  • Alteration in coagulation profile (eg, increased prothrombin time, decreased prothrombin time, prolonged bleeding and clotting times) is common.
• Urine chemistry
  • Urinalysis shows bile pigments.
  • Absence of urinary urobilinogen signifies complete obstruction.
• Tumor markers: Currently, no tumor marker is sensitive or specific enough to serve as reliable screening tools for this carcinoma.
  • Carbohydrate antigen (CA) 19-9 is the most studied and sensitive marker for pancreatic neoplasms at present. Unfortunately, CA 19-9 has almost no value in management of carcinoma of ampulla of Vater.
  • Carcinoembryonic antigen (CEA), DU-PAN-2, alpha-fetoprotein (AFP) and pancreatic oncofetal antigen (POA) also have been evaluated and found inaccurate.

Imaging Studies

• Abdominal ultrasonography
  • Advantages
    • Abdominal ultrasonography (US) is the most useful noninvasive initial investigation for distinguishing medical from surgical causes of jaundice. It is an inexpensive and readily available bedside procedure.
    • Abdominal US can identify dilated ducts, liver metastasis (in almost 90% of cases), ascites, and nodal metastasis.
    • Doppler US can be used to assess vascular involvement.
    • The level of obstruction can be assessed in 90% patients.
    • US-guided fine-needle aspiration (FNA) can be performed.
  • Limitations
    • Effectiveness is related to the skill of the user.
    • Very superficial lesions and very deep lesions may be missed. Distinguishing a metastasis from a hemangioma may be difficult.
    • Sensitivity is 80-90%, and information is inferior to that obtained by CT scan or MRI. Poor bowel preparation may obscure the important pathology.
• Endoscopic and laparoscopic ultrasonography
  • Endoscopic ultrasonography (EUS) is performed through a peroral route.
  • The test is highly sensitive in detecting major vascular involvement, which can prevent unnecessary surgery.⁵
  • EUS may identify tumors less than 1 cm in size.
  • Laparoscopic sonography can detect occult liver metastasis or peritoneal seeding missed by other imaging modalities.
  • Staging laparoscopy with laparoscopic ultrasonography may be more specific and accurate in predicting tumor resectability than laparoscopy alone (88% and 89% vs 50% and 65%, respectively⁶ ).
• CT scanning
  • Advantages
    • This modality is most useful when US is equivocal or when visualization is obscured by gas or ascites.
    • CT scan is superior to US, with an accuracy of more than 90%. CT scan findings correlate well with operative findings.
    • CT scan is better in evaluating operability and preoperative staging. It gives better assessment of invasion or compression of vessels and adjacent organs.
    • CT-guided biopsy may be obtained.
  • Disadvantages
    • Very ill patients may be unable to lie still or arrest respiration for the long periods required for high-quality imaging.
    • CT scan is more expensive than US and requires expertise in interpretation.
    • Potential radiation hazards exist for patients and staff.
    • Rare contrast reactions may occur.
    • Metal, stents, and clips may cause artifacts.
    • Very small tumors (<1 cm) may be missed.
• Magnetic resonance imaging
  • MRI is the most informative noninvasive method of evaluation currently available.
  • MRI cholangiopancreatography (MRCP) provides 94% accuracy in identifying the cause and extent of the pathology.
  • Results are reproducible.
  • With growing expertise in the use of magnetic imaging, diagnostic endoscopic retrograde cholangiopancreatography (ERCP) is quickly becoming obsolete.
• Radionucleotide scanning
  • The use of the hepatoiminodiacetic acid (HIDA) scan has declined in recent years.
  • This scan is better used for assessing liver parenchyma lesions or for possible help in diagnosing Budd-Chiari syndrome.
  • Use requires a qualified doctor and expensive equipment.
• Chest x-ray is performed to exclude pulmonary metastasis and other pulmonary diseases.

Other Tests

• ECG is performed to assess cardiac status, since surgery will be considered as a means of treatment.
• Nutritional studies should be ordered in preparation for surgery.

Procedures

• Endoscopic retrograde cholangiopancreatography
  • Advantages
    • ERCP allows diagnostic and therapeutic access to both the common bile duct and pancreatic duct.
    • The procedure displays the details of ductal anatomy and accurately demonstrates the level and nature of the obstruction. Anatomical variations in ducts can be evaluated carefully.

• ERCP allows therapeutic procedures, such as sphincterotomy, stenting, and nasobiliary drainage.
• It permits sampling of pancreatic juice, bile, and brush/grasp biopsy.
• Endoscopic excision of small periampullary tumors is gaining in popularity.
• Disadvantages
  • ERCP is an invasive procedure that requires an expert endoscopist/radiologist and a cooperative patient.
  • Very small tumors (<1 cm) can be missed.
  • ERCP is not possible if access to the duodenal papilla is difficult to obtain because of diverticula, anatomical ductal variations, or prior surgical bypass.
  • This procedure can precipitate pancreatitis and cholangitis.
  • Perforation and hemorrhage are 2 of the more serious complications.
• Percutaneous transhepatic cholangiography
  • Indications for this procedure, which is highly invasive, are very limited.
  • Percutaneous transhepatic cholangiography (PTC) is most useful when ERCP is unavailable or technically not feasible.
  • PTC can be useful in severely jaundiced patients when laparotomy or ERCP is not possible. Percutaneous transhepatic biliary drainage or transhepatic stenting may be the only option for some patients.
  • Biliary leakage may lead to peritonitis. Excessive bleeding from the puncture site and pneumothorax represent significant, but uncommon, complications.

Histologic Findings

In cases of ampullary tumors, preoperative endoscopic biopsy should be attempted, and carcinoma should be confirmed histologically or cytologically, if possible. If the specimen is insufficient or not representative, or if the histologic examination is inconclusive, surgery may be performed if a clinical suspicion exists. Approximately 90% of these tumors are adenocarcinomas. Neuroendocrine tumors, cystadenomas, and adenomas represent additional uncommon histologic types.

Staging

The tumor, node, metastases (TNM) classification and stage grouping is based on the Union Internationale Contre Cancrum (UICC) system, established in 1977, with separate classifications for pancreatic and periampullary carcinomas. The staging is important only to communicate a uniform definition of extent of disease. TNM classification and stage groups are as follows:

• T - Primary tumor
• Tx - The primary tumor cannot be assessed
• T0 - No sign of primary tumor
• Tis - Carcinoma in situ
• T1 - Tumor limited to the ampulla or sphincter of Oddi
• T2 - Tumor invading the wall of the duodenum
• T3 - Tumor invasion into the pancreas 2 cm or less
• T4 - More than 2 cm tumor invasion into the pancreas or any other adjacent organ

Peripancreatic tissue includes the surrounding retroperitoneal fatty tissue (retroperitoneal soft tissue or retroperitoneal space), including the mesentery (mesenteric fat), mesocolon, greater and lesser omentum, and peritoneum. Direct invasion of the bile ducts and the duodenum includes involvement of the ampulla.

Adjacent large vessels include the portal vein, the celiac trunk, the superior mesenteric artery and the common hepatic artery and vein (not the splenic vessels).

• N - Regional lymph nodes
• NX - Regional lymph nodes cannot be assessed
• N0 - No regional lymph node metastases
• N1 - Regional lymph node metastases

Subclassification of the category N1 into N1a (only 1 metastatic lymph node) and N1b (2 or more lymph nodes affected by metastases) is recommended, as the 2 categories appear to have marked prognostic differences. Total number of peripancreatic lymph nodes found in the surgical specimen must be mentioned.

• M - Distant metastases
• MX - Distant metastases cannot be assessed
• M0 - No distant metastases
• M1 - Distant metastases

Note: The splenic lymph nodes and those at the tail of the pancreas are not regional; metastases in these lymph nodes are classified as distant metastases (M1).

• Stage grouping of periampullary carcinoma
• Stage 1 - T1 N0 M0
• Stage 2 - T2 N0 M0, T3 N0 M0
• Stage 3 - T1 N1 M0, T2 NI M0, T3 N1 M0
• Stage 4 - T4 every N and every M, every T and N with M1
• Martin proposed a 4-stage system, as follows:
• Stage I - Vegetating tumor limited to the epithelium, with no involvement of the Oddi sphincter
• Stage II - Tumor localized in the duodenal submucosa without involvement of the duodenal muscularis propria but possible involvement of the sphincter of Oddi
• Stage III - Tumor involving the duodenal muscularis propria
• Stage IV - Tumor involving the periduodenal area or the pancreas, with proximal or distal lymph node involvement

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