Carcinoma of the Ampulla of Vater Workup

Updated: May 08, 2018
  • Author: Nafisa K Kuwajerwala, MD; Chief Editor: N Joseph Espat, MD, MS, FACS  more...
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Workup

Laboratory Studies

Blood biochemistry

 Recommended tests and possible findings include the following:

  • Complete blood cell count (CDB): May show anemia caused by bleeding from the ampullary mass

  • Bilirubin: May show hyperbilirubinemia (conjugated type) due to blockage of the biliary outflow

  • Alkaline phosphatase: May be elevated due to biliary obstruction.

  • Liver function studies: Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) rise in long-standing obstruction. Elevation of AST is significantly more common in unresectable lesions (83%) than in resected lesions (22%). [8]

  • Serum amylase: A rise in serum amylase level may be seen in 30% of patients. [8]

  • Coagulation profile: Increased prothrombin time and prolonged bleeding and clotting times may be seen in profound obstructive jaundice.

Urine chemistry

Urinalysis may show 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. Cancer antigen (CA) 19-9 is the most studied and sensitive marker for pancreaticobiliary neoplasms at present; however, a normal serum CA 19-9 level does not rule out pancreaticobiliary malignancy. The following markers have been evaluated and found inaccurate:

  • Carcinoembryonic antigen (CEA)

  • DU-PAN-2

  • Alpha-fetoprotein (AFP)

  • Pancreatic oncofetal antigen (POA) 

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Imaging Studies

Abdominal ultrasonography

Advantages of abdominal ultrasonography (US) include the following:

  • Abdominal 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% of patients.

  • US-guided fine-needle aspiration (FNA) can be performed.

Limitations of abdominal US are as follows:

  • 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.

  • It has been found to be diagnostic of carcinoma of ampulla of Vater only in 23.8% cases.

Endoscopic ultrasonography and transpapillary ultrasonography

Endoscopic ultrasonography (EUS) is performed through a peroral route. EUS remains highly operator dependent. It offers an additional option for biopsy. The test is highly sensitive in detecting major vascular involvement, which can prevent unnecessary surgery. [14]

EUS may identify tumors less than 1 cm in size. EUS is the most sensitive tool for diagnosis and staging of carcinoma of the ampulla of Vater. The sensitivity for detection is 97%, for T staging, 72%; for nodal staging, 47%; and for determining vascular involvement, 100%. However, the presence of biliary stent can decrease the accuracy to some extent. It can also be coupled along with biliary stenting. However, the sensitivity is low for determining distant metastasis.

Laparoscopic sonography can detect occult liver metastasis. 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%, respectively [15] ).

Computed tomography

Advantages are as follows: 

  • CT is noninvasive.

  • CT scan is superior to US but inferior to EUS for carcinoma of the ampulla of Vater unless extensive tumor is present.

  • CT scan is better in evaluating resectability and preoperative staging. It gives better assessment of invasion, encasement, or compression of vessels and adjacent organs.

  • CT-guided biopsy may be obtained when mass lesions are present, but endoscopic biopsy is preferred.

  • Simultaneous dilatation of the common bile duct and the pancreatic duct (the double duct sign) may be seen in obstruction from ampulla of Vater cancer, but is not specific for this disease [49] ; see the images below.

    Double duct sign of periampullary cancers. Note th Double duct sign of periampullary cancers. Note the dilated common bile duct as well as the pancreatic duct. Liver metastatic lesion is also seen.
    Distended gall bladder with double duct sign in a Distended gall bladder with double duct sign in a patient with periampullary cancer.

Disadvantages of CT are as follows:

  • 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 or contrast nephropathy 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. An MRCP revealing a resectable mass may preclude the need for endoscopic retrograde cholangiopancreatography (ERCP).

Radiography

Chest radiography is performed to exclude pulmonary metastasis and other pulmonary diseases.

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Other Tests

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

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Procedures

Endoscopic retrograde cholangiopancreatography

Advantages of this procedure are are as follows: 

  • 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.

    Endoscopic view of an ampullary carcinoma. Endoscopic view of an ampullary carcinoma.
  • 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.

  • Ahn et al reported that preoperative ERCP was an independent risk factor for postoperative recurrence in patients with ampulla of Vater cancer; ERCP was associated with a significantly higher rate of early distant metastasis within 1 year, especially in patients with early-stage disease. [48]

Percutaneous transhepatic cholangiography

Indications for percutaneous transhepatic cholangiography (PTC), which is highly invasive, are very limited. 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.

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Histologic Findings

In the Surveillance, Epidemiology, and End Results (SEER) database, adenocarcinoma is the most frequently identified histology for ampullary cancer. Histologic types and frequency were as follows [1] :

  1. Adenocarcinoma not otherwise specified (NOS): 65% of cases
  2. Carcinoma (NOS): 8.1%
  3. Adenocarcinoma arising from adenoma (adenocarcinoma in villous adenoma, in tubulovillous adenoma, in adenomatous polyp and villous adenocarcinoma): 7.5%.
  4. Papillary adenocarcinoma: 5.6%
  5. Mucinous adenocarcinoma: 4.7%
  6. Signet ring cell carcinoma: 2%

Adenocarcinoma is categorized as intestinal type or biliopancreatic type, which may have prognostic implications. Intestinal type has columnar cells organized into tubular or cribriform glands. Biliopancreatic type consist of cuboidal or low columnar cells arranged into simple glands or papillary or micropapillary structures. [4]

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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. 

T (primary tumor) classification is as follows:

  • 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) classification is as follows:

  • 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 documented.

M (distant metastases) classification is as follows:

  • 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 is as follows:

  • 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 any N any M; any T any N  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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