Chapter 34 Tumors of the biliary tract
2 Carcinoma of the gallbladder, because of its late stage of presentation, has an overall 5-year survival of less than 10%.
3 Aggressive surgical resection, including partial hepatectomy, may result in increased survival in patients with cancers limited to the gallbladder wall.
4 Cholangiocarcinoma is strongly associated with cystic disease of the biliary tree (choledochal cysts, Caroli’s disease), Clonorchis sinensis infection, primary sclerosing cholangitis, and hepatolithiasis.
5 Patients with proximal (hilar) cholangiocarcinomas have poor overall survival, although aggressive resection that includes hepatectomy to achieve negative margins may improve the outcome.
Benign Tumors of the Gallbladder
Pseudopolyps (Cholesterol Polyps)
1. The most commonly observed polypoid lesion of the gallbladder; accounts for approximately 50% of such lesions
2. Not a true neoplasm, but rather cholesterol-filled projections of gallbladder mucosa protruding into the lumen
3. Usually less than 1 cm in size; visualized on gallbladder imaging studies (ultrasonography, oral cholecystography) as nonmobile filling defects
Adenomyosis
2. Three types: fundal (most common), appearing as a hemispheric lesion with a central dimple; segmental, consisting of an annular stricture; or diffuse, involving the entire gallbladder
3. May manifest as muscular hypertrophy secondary to gallbladder dysmotility; therefore, symptoms are relieved by cholecystectomy
Adenomas
2. Usually manifest as solitary, nonmobile filling defects seen on gallbladder ultrasonography or oral cholecystography
Treatment
1. Because the histology of polypoid lesions of the gallbladder cannot be determined nonoperatively by current methods, patients with polyps larger than 1 cm should undergo cholecystectomy.
2. Polyps up to 1 cm in size, regardless of total number, should be followed by repeat imaging studies every 3 to 6 months.
Benign Tumors of the Bile Duct
4. Symptoms are usually caused by bile duct obstruction, which results in intermittent jaundice or cholangitis.
5. The diagnosis can usually be made by magnetic resonance, endoscopic retrograde, or percutaneous transhepatic cholangiography.
6. Treatment consists of surgical resection of the bile duct, most commonly with reconstruction by hepaticojejunostomy.
Carcinoma of the Gallbladder
Incidence
1. Carcinoma of the gallbladder is the most common biliary tract malignancy and the fifth most common gastrointestinal cancer (3% to 4% of gastrointestinal tumors).
2. The incidence has increased as the population has aged. Currently, 6000 to 7000 new cases are diagnosed each year (2.5 cases per 100,000 population).
5. An increased incidence is seen in southwestern Native Americans, Native Alaskans, Mexicans, and Hispanics living in the United States and in residents of northern Japan, Israel, and Chile.
Etiology
Risk factors for gallbladder carcinoma:
1. Gallstones/chronic cholecystitis
Gallstones are present in more than 90% of patients with gallbladder carcinoma; conversely, only 1% of patients with gallstones have gallbladder carcinoma.
Larger stones (>3 cm) are associated with a 10-fold higher risk of gallbladder cancer compared with smaller stones.
The role of gallstones in the development of gallbladder cancer is likely related to chronic inflammation.
2. Choledochal cysts (see Chapter 33)
Choledochal cysts are associated with carcinomas throughout the biliary tract including the gallbladder.
The risk may be related to an association with an anomalous pancreaticobiliary duct junction, which is frequently seen with choledochal cysts.
3. Anomalous pancreaticobiliary duct junction
The long common channel of the pancreatic and common bile duct (type 3B anomaly) appears to be associated with a significantly increased risk of gallbladder cancer.
5. Estrogens: This epidemiologic association may simply be related to the associated increased incidence of gallstones.
7. Gallbladder wall calcification: Diffuse calcification of the gallbladder wall (porcelain gallbladder) was formerly an indication for cholecystectomy because of the risk of cancer even in asymptomatic patients. More recent studies have suggested that this risk had been overestimated and is likely less than 5%. Calcification of the gallbladder mucosa is associated with a higher incidence of gallbladder cancer.
Pathology and staging
2. Routes of spread
b. Lymphatic drainage is to the adjacent lymph node basins first—cystic duct, pericholedochal, and hilar lymph nodes (N1). Secondary basins include the retropancreatic, celiac axis, and periaortic nodes (N2).
c. The veins of the gallbladder drain directly into the liver parenchyma and to branches of the portal vein of segments V and IVB of the liver.
Stage 0 | Carcinoma in situ (T0) |
---|---|
Stage I (T1N0M0) | Tumor invades lamina propria (T1a) or muscular layer (T1b) |
Stage II (T2N0M0) | Tumor invades perimuscular connective tissue; no extension beyond serosa or into liver (T2) |
Stage IIIA (T3N0M0) | Tumor perforates the serosa (visceral peritoneum) and/or directly invades the liver and/or one other adjacent organ, such as stomach, duodenum, colon, pancreas, or extrahepatic bile ducts (T3); no lymph node involvement |
Stage IIIB (T1–3N1M0) | T1–3 with positive nodes confined to the hepatic hilus including nodes along the bile duct, hepatic artery, portal vein, and cystic duct (N1) |
Stage IVA (T4N0M0) | Tumor invades main portal vein or hepatic artery or invades two or more extrahepatic organs (T4); no lymph node involvement |
Stage IVB (any T, any N, M1 or any T N2M0 or T4N1M0) | Any T with distant metastases (M1); any T with lymph node metastases to celiac, periduodenal, peripancreatic, and/or superior mesenteric lymph nodes (N2); T4 with N1 nodes |
Adapted from Edge S, Byrd D, Compton C, et al. AJCC Cancer Staging Manual, 7th ed. New York: Springer-Verlag, 2010.
Clinical features
1. Symptoms (frequency)
Abdominal pain (80%): usually of less than 1 month’s duration and difficult to distinguish from symptoms of acute cholecystitis or biliary pain
Diagnosis and preoperative staging
1. Laboratory tests
Abnormal liver biochemical test levels when tumor or periportal lymphadenopathy is associated with biliary obstruction
2. Radiologic studies
b. Computed tomography (CT)
Findings are similar to those of ultrasonography with respect to gallbladder wall thickening or mass.