You are in: eMedicine Specialties > Radiology > GASTROINTESTINAL Gallbladder, CarcinomaArticle Last Updated: Aug 29, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: Gregory M Szarnecki, MD, Consulting Staff, Department of Radiology, Columbia Regional Hospital, Columbia, MO Gregory M Szarnecki is a member of the following medical societies: American College of Radiology and American Society of Neuroradiology Coauthor(s): Ian G Karol, MD, Chief, Section of Body Imaging, Associate Program Director, Department of Radiology, Bridgeport Hospital Yale New Haven Health, Yale School of Medicine; Hanan Khalil, MD, Staff Physician, Department of Diagnostic Radiology, Bridgeport Hospital Yale New Haven Health Editors: Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand; Abraham H Dachman, MD, FACR, Professor, Department of Radiology, The University of Chicago School of Medicine; Director of CT, Department of Radiology, The University of Chicago Hospitals; Robert M Krasny, MD, Consulting Staff, Department of Radiology, The Angeles Clinic and Research Institute; John Karani, MBBS, FRCR, Consulting Staff, Department of Radiology, King's College Hospital, London Author and Editor Disclosure Synonyms and related keywords: GB carcinoma, gallbladder cancer, hepatobiliary carcinoma INTRODUCTIONSection 2 of 11
  BackgroundAlthough uncommon, carcinoma of the gallbladder (GB) is the most common primary hepatobiliary carcinoma, is the fifth most common malignancy of the GI tract, and predominantly affects older persons with long-standing cholecystolithiasis. GB epithelial tumors tend to behave similarly to other GI adenocarcinomas. When the diagnosis is made incidentally at the time of cholecystectomy, surgical resection can be curative; however, more commonly, the tumor is unresectable and rarely diagnosed preoperatively despite patients' symptoms. Early diagnosis can improve the clinical outcome and cure rate of GB carcinoma. PathophysiologyThe exact etiology of GB carcinoma is unknown; however, several associated factors have been identified. One hypothesis suggests that irritation of the GB mucosa by stones causes chronic inflammation and, followed by repetitive epithelial repair, may cause malignant transformation. Approximately 15 years is required for dysplasia to progress to invasive carcinoma. Classification
Location: In affected patients, 60% of GB tumors occur in the fundus, 30% in the GB body, and 10% in the GB neck. Spread
Staging: Several staging systems exist. A simplified version of the American Joint Commission on Cancer (AJCC) staging (or tumor, node, metastasis [TNM] staging) is shown in Table 11: Table 1. AJCC Classification1
Table 3. Modified Nevin-Moran Staging2
FrequencyUnited StatesIn the general population, the reported incidence of GB carcinoma is 3 cases per 100,000 persons, with more than 6500 new patients diagnosed annually. This condition is found incidentally in 1-3% of cholecystectomy specimens and in 0.5-2.4% of postmortem examinations. InternationalWorldwide, Chile and Bolivia have the highest prevalence of GB carcinoma. In Japan, there are 4.8 cases per 100,000 males and 5 cases per 100,000 females. In Israel, there are 7.5 cases per 100,000 males and 13.8 cases per 100,000 females. In Poland, the incidence rate is 4.8 cases per 100,000 males and 23.1 cases per 100,000 females. The disease is also seen in Northern Europe and South Africa. Mortality/MorbidityPatients with GB carcinoma have an overall mean survival rate of 6 months, and the 5-year survival rate is 5%.3 RaceIn Native Americans, GB carcinoma is the most commonly seen gastrointestinal malignancy, with a reported incidence rate of 5.1 cases per 100,000 males and 8.7 cases per 100,000 females. This condition is also seen in Hispanic Americans and Latin Americans. In addition, GB carcinoma is twice as common in whites as in blacks. SexGB carcinoma has a female preponderance. The female-to-male ratio is 3:1. AgeThe greatest incidence of GB carcinoma is in persons older than 65 years. Clinical DetailsAssociated findings and risk factors for GB carcinoma are as follows:
Presentation The signs and symptoms of GB carcinoma are nonspecific.
Treatment and prognosis No established treatment protocol exists. Radical surgery with negative tumor margins is an accepted treatment for advanced disease. If there are negative tumor margins, 5-year survival rates are as follows, according to the AJCC 2:
Clinical problems In most patients, the diagnosis of GB carcinoma is made postoperatively and at an advanced stage of the disease because of the poorly defined GB muscularis that allows early spread into the perimuscular tissue and, frequently, beyond the GB to involve the liver and extrahepatic biliary ducts. Preferred ExaminationUltrasound (US), which is readily available, noninvasive, and cost-effective, is the imaging modality of choice. Limitations of TechniquesUS cannot stage the tumor. The visualization of lymph nodes, intraperitoneal disease, and distant metastases is difficult. DIFFERENTIALSSection 3 of 11
Cholecystitis, Acute Hepatocellular Carcinoma Liver, Metastases Porcelain Gallbladder Other Problems to Be ConsideredChronic cholecystitis
RADIOGRAPHSection 4 of 11
FindingsPlain abdominal radiographic films have a limited role in GB carcinoma. The images may demonstrate porcelain GB, calcified gallstones, and, rarely, biliary gas from GB-enteric fistula. Mucinous tumors may produce vague or punctate calcification in the primary tumor or in metastatic foci that may be visible on plain films. Barium studies, if positive, show duodenal invasion and displacement. Transverse colon invasion may occasionally be seen. CT SCANSection 5 of 11
FindingsComputed tomography (CT) scanning can detect GB masses and thickening of the GB wall, as well as the extent of hepatic invasion (see Images 3-4). Peritoneal or distant disease, although uncommon, can be seen. Three patterns of findings are identified on CT scans as follows:
False Positives/NegativesXanthogranulomatous cholecystitis is an inflammatory process that cannot be reliably distinguished from GB carcinoma on CT scans because of multiple overlapping features such as GB wall thickening and involvement of the surrounding tissues, including portal lymph nodes, fat, and the liver. MRISection 6 of 11
FindingsUntil recently, few reports in the MRI literature addressed the diagnosis of GB carcinoma, and this modality is not commonly used in the diagnostic process. The findings are analogous to CT scanning. The tumor is usually bright on T2-weighted images and is poorly marginated. On T1-weighted images, relative to the liver, the GB carcinoma ranges from isointense to hypointense. ULTRASOUNDSection 7 of 11
FindingsUS is the most commonly used imaging modality for evaluating GB carcinoma; however, there have been no identified pathognomonic findings. Indirect signs that suggest the presence of GB carcinoma are as follows:
Degree of ConfidenceA mass that arises from the GB may be difficult to differentiate from a mass that arises from the liver. The visualization of gallstones located centrally in a solid mass can help make the diagnosis. Benign causes of GB wall thickening can mimic carcinoma, and smaller polyps are often benign (see Ultrasound, False Positives/Negatives). False Positives/NegativesGB wall thickening is nonspecific and may be seen in multiple medical conditions, including acute and chronic cholecystitis, heart failure, hypoalbuminemia, hepatitis, and cirrhosis. However, the GB wall thickening in these patients is usually diffuse in contrast to the focal thickening in patients who have GB carcinoma. Adenomyomatosis can also cause focal GB wall thickening. This benign condition may mimic a GB tumor. US may demonstrate focal or diffuse wall thickening, with echogenic foci in Rokitansky-Aschoff sinuses that are often seen as "comet-tail" reverberation artifacts. Benign polypoid lesions are difficult to distinguish from polypoid carcinoma; the cauliflower-like appearance suggests malignancy. Polyps smaller than 5 mm are unlikely to be malignant; polypoid lesions that are 5-10 mm in size should be followed up. In a patient with melanoma, metastases can cause multiple polypoid lesions. Tumefactive sludge can also mimic an intraluminal mass; usually, this is easy to differentiate by demonstrating the mobility of the sludge. Color Doppler US can also be used; the presence of flow within the lesion indicates that it is a solid mass rather than sludge. The sensitivity of endoscopic US in the detection of GB carcinoma is expected to increase in the future. NUCLEAR MEDICINESection 8 of 11
FindingsNonopacification of the GB on cholescintigraphy with technetium-99m (99mTc) iminodiacetic acid analogue scanning is a nonspecific sign that indicates the possibility of carcinoma. This modality has generally been replaced by US and is not used commonly. ANGIOGRAPHYSection 9 of 11
FindingsAngiography may demonstrate neovascularity that arises from the cystic arteries, as well as arterial and venous encasement in the area of the GB, although this modality is not used as a diagnostic tool. MULTIMEDIASection 10 of 11
REFERENCESSection 11 of 11
Gallbladder, Carcinoma excerpt Article Last Updated: Aug 29, 2007 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
