You are in: eMedicine Specialties > Radiology > GASTROINTESTINAL Biliary Cystadenoma/CystadenocarcinomaArticle Last Updated: Jun 6, 2007AUTHOR AND EDITOR INFORMATIONSection 1 of 12
  Author: Mohammad Alobaidi, MD, Diagnostic Radiologist, River Oaks Imaging and Diagnostics, Spencer Radiology Mohammad Alobaidi is a member of the following medical societies: American College of Radiology, American Roentgen Ray Society, Radiological Society of North America, and Texas Medical Association Coauthor(s): Ali Shirkhoda, MD, Director, Division of Diagnostic Imaging, William Beaumont Hospital; Clinical Professor of Radiology, University of California in Irvine and Wayne State University Editors: John L Haddad, MD, Clinical Associate Professor, Department of Radiology, Weill Medical College of Cornell University; Director of Body MRI, Department of Radiology, Methodist Hospital in Houston; Bernard D Coombs, MB, ChB, PhD, Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand; Paul M Silverman, MD, Professor, Chief of Body Imaging, Chair in Diagnostic Imaging, Department of Radiology, University of Texas MD Anderson Cancer Center; 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: bile duct cystadenoma, bile duct cystadenocarcinoma, hepatic neoplasm, intrahepatic cyst, extrahepatic cyst, benign hepatic lesion, hepatic cysts, multilocular cyst, hepatomegaly, ovarian stroma INTRODUCTIONSection 2 of 12
  BackgroundBiliary cystadenoma represents a rare benign cystic hepatic neoplasm that has premalignant potential. The tumor originates in the bile ducts and is lined by mucin-secreting columnar or cuboidal epithelium. Biliary cystadenoma can appear as a unilocular or multilocular cystic intrahepatic mass. The malignant counterpart is biliary cystadenocarcinoma, which is believed to arise from the premalignant form. PathophysiologyGrossly, biliary cystadenomas and cystadenocarcinomas are usually multilocular cysts that have internal septa and nodularity of the inner wall. In a study, the presence of septa without nodularity was seen only in cystadenomas. The internal fluid content of the cystic cavity often consists of a high-molecular-weight glycoprotein called mucin. However, hemorrhagic, bilious, clear, and mixed-fluid contents have also been observed. Histologically, biliary cystadenomas and cystadenocarcinomas are lined by cuboidal or columnar epithelium and surrounded by dense collagenous tissue. The tumor cells are well differentiated and have malignant predisposition with invasion of the basement membrane. More aggressive tumors penetrate the surrounding hepatic parenchyma or even the diaphragm. The collagenous tissue surrounding the cavity is lined by inflammatory cells and, occasionally, by lipid-laden macrophages. The lesions are similar to mucinous cystic tumors in that they arise in the pancreas and ovaries. Hytiroglou et al reported a case in which cystadenocarcinoma of the liver with 2 histologic cell types was described.1 One cell type contained clear cytoplasm with mucin, whereas the other cell type contained eosinophilic cytoplasm that displayed hepatocytic features, indicating that biliary cystadenomas may contain a subpopulation of tumor cells with a hepatocytic appearance that was previously unknown. This observation demonstrates a possible practical application of immunohistochemical staining to differentiate hepatocellular carcinoma from biliary cystadenocarcinoma. Cystadenocarcinomas have been divided into 2 subgroups based on pathologic and histologic features that determine the patient's prognosis. The presence of ovarian stroma in females is believed to be a better prognostic indicator,2 although differentiation based on morphology is not reliable. Furthermore, immunohistochemical analysis has been used to differentiate cystadenocarcinomas in patients with a favorable outcome from cystadenocarcinomas in patients with a poor outcome.3, 4 Several mucin core protein genes have been isolated, including MUC1, which is expressed in invasive ductal carcinomas of the pancreas and invasive cholangiocarcinomas; MUC1is associated with poor prognosis.3, 4 MUC2 expression, however, is associated with a better prognosis and is expressed in intraductal papillary mucinous tumors of the pancreas, as well as in biliary cystadenocarcinomas. FrequencyInternationalApproximately 100 cases of cystadenomas and 50 cases of cystadenocarcinomas have been reported worldwide. These lesions account for less than 5% of all patients with intrahepatic cysts.5 Approximately 85% of cystadenomas and cystadenocarcinomas are found in the intrahepatic portions of the biliary ducts, whereas 15% are in the extrahepatic ducts. A slight predilection is seen for the right hepatic lobe; however, lesions have been found in both hepatic lobes in as many as 25% of patients. Mortality/Morbidity
RaceBiliary cystadenocarcinoma occurs more frequently in whites than in other races. Sex
AgeBiliary cystadenoma is found mostly in those who are middle-aged, with a peak incidence in people aged 40-50 years. More than 75% of patients are older than 30 years. Clinical DetailsThe evaluation of patients with cystic liver disease is challenging because the primary problem is distinguishing benign disease from malignant disease. Patients often present with nonspecific clinical symptoms, or they may be asymptomatic. Most patients with benign developmental cystic disease are asymptomatic, and the disease is discovered incidentally, although approximately one third of patients complain of right upper quadrant abdominal discomfort. In 25% of patients with benign disease, hepatomegaly is noted on physical examination. Abdominal swelling, dyspepsia, nausea, and vomiting are other nonspecific findings in patients with benign or malignant lesions. Obstructive jaundice is extremely unusual in benign cystic diseases and, if present, should raise a clinical suspicion of neoplasm. The differential diagnoses for a patient who presents with an upper abdominal mass and pain include cystic lesions, solid neoplasms, and lesions resulting from trauma. The workup of patients with hepatic cysts should begin with laboratory evaluation; liver function findings are usually normal, and red blood cell and white blood cell counts should be obtained to exclude anemia or infection. When a lesion is diagnosed as benign, both clinical and radiologic findings are used to obtain a degree of certainty in the diagnosis. Short of tissue biopsy, the clinician and radiologist must interpret findings within the appropriate clinical context. This interpretation is more difficult if a cystic lesion is identified in a patient with a previously known malignancy. The most difficult decision that needs to be made is whether intervention is needed in the patient who has a hepatic cyst. If malignancy is suspected and if the radiologic findings are equivocal, then the diagnosis must be made by tissue analysis. A tissue sample is usually obtained surgically, although some centers may attempt image-guided biopsy. The possible risk for hemorrhage with image-guided biopsy is a result of the vascular nature of the liver. The major indications for surgery are pain, rupture, hemorrhage, infection, and a strong suggestion of malignancy. Preferred ExaminationDiagnostic imaging is an integral part of the patient evaluation for cystic lesions in the liver. Although the 3 primary imaging modalities are ultrasonography, computed tomography (CT) scanning, and magnetic resonance imaging (MRI), ultrasonography should be the initial screening modality. However, CT scanning and, occasionally, MRI may be needed to determine the exact location and extent of the disease. Limitations of TechniquesIn general, all 3 imaging modalities have inherent limitations. In published studies, CT scanning was less sensitive in correctly identifying septa within a cystic lesion.6, 7, 8 Ultrasonography is more reliable in correctly diagnosing the degree of septation, which is a predominant feature of both cystadenomas and cystadenocarcinomas. Papillary projections can be seen with both CT scanning and ultrasonography. MRI signal characteristics of biliary cystadenoma/cystadenocarcinoma are not specific for the disease. The cyst often appears hypointense on T1-weighted images and hyperintense on T2-weighted images, similar to other fluid-filled cystic lesions. Furthermore, depending on the fluid content of the cyst, the T1- and T2-signal characteristics can vary. DIFFERENTIALSSection 3 of 12
Autosomal Dominant Polycystic Kidney Disease Choledochal Cyst Hepatic Adenoma Hepatocellular Carcinoma Liver, Metastases Other Problems to Be ConsideredAbscess
RADIOGRAPHSection 4 of 12
FindingsPlain radiographic results are nonspecific, and the images may show few or no findings. Possible findings include coarse curvilinear calcifications in the right upper abdominal quadrant and elevation of the right hemidiaphragm, if hepatomegaly or right pleural effusion is present. Degree of ConfidenceCertain features of biliary cystadenomas and cystadenocarcinomas may suggest a more aggressive lesion; however, radiographic distinction is difficult. Both tumors are multiloculated, hypoattenuating, and enhancing after the administration of contrast material. Generally, cystadenocarcinomas may exhibit coarse calcifications and mural nodules. CT SCANSection 5 of 12
Findings
Degree of ConfidenceDifferentiating biliary cystadenoma from cystadenocarcinoma with imaging criteria may not be possible in many patients. This concern, however, is considered to be less important therapeutically than academically, as treatments are similar in patients with either tumor because of the premalignant nature of biliary cystadenomas. However, cystadenomas and cystadenocarcinomas must be differentiated from other cystic liver lesions. False Positives/NegativesCongenital hepatic cysts can mimic cystadenomas or cystadenocarcinomas because all are cystic intrahepatic lesions that are filled with low-attenuating fluid. The clinical implication is important because the treatment options differ greatly among these conditions. Generally, biliary cystadenomas and cystadenocarcinomas are solitary lesions, whereas congenital hepatic cysts tend to be multiple. However, the differentiation among these can be difficult because they are slow growing. Alternatively, large intrahepatic congenital cysts may be mistaken for premalignant cystadenoma or even malignant cystadenocarcinoma, especially if the congenital cyst is depicted as septate or complex on CT scans. Liver abscesses and hydatid disease of the liver can present as septate or multiloculated cystic masses on CT scans. These infectious diseases can be evaluated with laboratory findings. MRISection 6 of 12
FindingsThe diagnostic role of MRI is to better define the lesion, to verify the CT scan and ultrasonographic characteristics, and to exclude conditions that mimic these tumors, such as cystic hepatocellular carcinoma. MRI findings of biliary cystadenoma have been shown to correlate well with the gross pathologic findings. The mass is typically a fluid-containing multilocular cyst with homogeneous low signal intensity on T1-weighted images and homogeneous high signal intensity on T2-weighted images. Depending on the content of the cystic fluid, T1- and T2-weighted images may demonstrate variable intermediate signal intensities. Degree of ConfidenceAs with CT scan examination, using MRI to differentiate biliary cystadenoma from cystadenocarcinoma is difficult in many patients, although MRIs may show septa better than CT scans. However, ultrasonography is the most sensitive of the 3 primary imaging modalities for detecting the presence and degree of septation. In addition, calcifications are poorly imaged with MRI; thus, calcification is not used as an MRI criterion for the diagnosis of biliary cystadenocarcinoma. Nonetheless, MRI can be helpful in differentiating cystadenomas and cystadenocarcinomas from other cystic liver lesions on the basis of several criteria. Generally, inflammatory lesions tend to show a greater degree of wall enhancement on MRIs than on CT scans. Abscesses usually show increased rim enhancement, which has been described as caused by the degree of capillary permeability in the surrounding liver parenchyma. However, although the surrounding edema is not typically a helpful finding because it occurs in both abscesses and cystadenocarcinomas, the presence of edema can help to differentiate abscess formation from benign biliary cystadenoma, which tends not to form pericystic edema. In addition, the presence of air within a hepatic abscess on MRI is diagnostic for an air-forming organism and appears as a signal void. Air can also be recognized on CT scans, if present. The most common cystic subtype of primary liver neoplasm is hepatocellular carcinoma. Chronic hepatitis B and hepatitis C are the major risk factors for liver cirrhosis, which accounts for approximately 60-90% of all hepatocellular carcinomas. On CT scans or MRIs, signs of coexistent cirrhosis, such as ascites, macronodules, or hepatomegaly, help clinicians and radiologists differentiate cystic hepatocellular carcinoma from biliary cystadenocarcinoma. False Positives/NegativesFindings of low signal intensity on T1-weighted images and high signal intensity on T2-weighted images are not specific for cystadenoma or cystadenocarcinoma, as many other cystic hepatic lesions show this type of signal-intensity pattern. However, MRI can be helpful in differentiating among such cystic hepatic lesions on the basis of other criteria. ULTRASOUNDSection 7 of 12
FindingsThe characteristic ultrasonographic finding for biliary cystadenoma or cystadenocarcinoma is an anechoic mass with echogenic internal septations. Papillary projections into the cystic space may be seen. Degree of ConfidenceOften, ultrasonography cannot be used as a reliable means for defining the exact anatomy or for determining the degree of disease involvement. These roles are better reserved for CT scanning and MRI; however, the differentiation of simple cysts from biliary cystadenomas or cystadenocarcinomas should almost always be possible on the basis of ultrasonographic and CT-scan criteria. False Positives/NegativesOn sonograms, a congenital hepatic cyst can mimic any cystic hepatic lesion, particularly if the cyst is multiloculated. Generally, the presence of a multiloculated anechoic cyst, as depicted on sonograms, warrants further investigation by CT scanning, as does a cystic lesion that appears to enlarge over time or that develops other signs of the malignant potential seen in biliary cystadenocarcinoma. Liver abscesses and hydatid disease of the liver can present as septate or multiloculated cystic masses on sonograms. These infectious diseases can be evaluated with laboratory findings. NUCLEAR MEDICINESection 8 of 12
FindingsNuclear medicine has no role in the diagnosis of biliary cystadenoma or cystadenocarcinoma, although studies with this modality may show a photopenic area in the liver, which is nonspecific. ANGIOGRAPHYSection 9 of 12
FindingsThe diagnosis of biliary cystadenoma and cystadenocarcinoma is best made by using conventional imaging modalities. Angiographic evaluation may reveal an avascular mass, as opposed to hepatocellular carcinoma or cystic metastasis, but plays a limited role in the diagnosis of biliary cystadenoma and cystadenocarcinoma. As with other cystic lesions in the liver, displacement of blood vessels may be demonstrated. INTERVENTIONSection 10 of 12
The accepted definitive treatment for biliary cystadenoma and cystadenocarcinoma is surgical resection. No surgical distinction is made between cystadenoma and its malignant counterpart because cystadenomas are at risk for malignant degeneration. Thus, the surgical intervention is identical for both. Recurrence, malignant transformation of biliary cystadenoma into cystadenocarcinoma, or both are major indications for total surgical excision. The decision to resect the lesion should be based on the overall patient surgical suitability. Factors include the patient's age and comorbidities, the likelihood of anatomic resectability, and the patient's hepatic function status. Unlike hypervascular hepatocellular carcinoma, selective nonsurgical treatments, such as hepatic artery ligation, arterial embolization, and tumor injection, are not options in biliary cystadenoma and cystadenocarcinoma because these lesions are generally avascular or hypovascular. Even in the setting of surgical resection, recurrence is common; biliary cystadenocarcinomas have a relatively high recurrence rate after total surgical cystectomy. Medical treatment has no role in cases of biliary cystadenoma or cystadenocarcinoma. In the rare patient who has a cystic hepatic lesion of uncertain etiology or of malignant potential, the clinician's decision to observe the lesion or to resect is difficult to make. Indications for resection of lesions with equivocal findings include pain, hemorrhage, rupture, and infection. Medical/Legal Pitfalls
MULTIMEDIASection 11 of 12
REFERENCESSection 12 of 12
Biliary Cystadenoma/Cystadenocarcinoma excerpt Article Last Updated: Jun 6, 2007 | ||||||||||||||||||||||||||||
