Answer for BIR CoW 18 Dec 2022
Mass forming cholangiocarcinoma
Findings
evidence of illdefined T2 heterointense lesion with focally dilated intrahepatic biliary radicles noted in segment 7/8 of right lobe of liver , with subtle capsular retraction , which on contrast administration shows delayed enhancement
Discussion
Mass-forming intrahepatic cholangiocarcinomas (MF-ICC), also referred as peripheral cholangiocarcinomas, comprise one of the three recognized growth patterns of intrahepatic cholangiocarcinomas. On imaging, these tumors usually present as large and relatively well-defined hepatic masses with lobulated margins and showing peripheral rim enhancement. They are often associated with peripheral biliary dilatation. Epidemiology Mass-forming intrahepatic cholangiocarcinomas are associated with chronic liver diseases, including viral hepatitis . Clinical presentation These tumors tend to present late as larger masses as they rarely cause symptoms when smaller, early in their natural history Pathology The mass-forming subtype is the most common among the intrahepatic cholangiocarcinomas General morphological features that commonly guide radiologists to the diagnosis of mass-forming intrahepatic cholangiocarcinoma are the associated capsular retraction and distal bile duct dilatation. The enhancement pattern seen on post-contrast dynamic images can be quite variable, depending on tumor size and degree of differentiation. Be aware that enhancement features of mass-forming intrahepatic cholangiocarcinoma and hepatocellular carcinomas can overlap when tumors are smaller than 3 cm and in cirrhotic livers CT Mass-forming cholangiocarcinomas are relatively well-defined and markedly hypodense on the non-contrast studies. On dynamic post-contrast scans: there is minor peripheral rim enhancement during both the arterial and portal venous phases arterial enhancement has been associated with better prognosis 6 the central part of the tumor usually does not enhance during the early phases, but frequently show gradual centripetal prolonged enhancement at delayed-phases 1,2,4 rate and extent of enhancement depend on the degree of central fibrosis 1 The bile ducts distal to the mass are typically dilated. Again, capsular retraction may be evident and is highly suggestive of this etiology. Lobar or segmental hepatic atrophy is usually associated with vascular invasion 3. Although narrowing of the portal veins (or less frequently, hepatic veins) is seen, unlike hepatocellular carcinoma, cholangiocarciMRIT1: hypointense 7 T2: hyperintense 7 DWI: target sign of diffusion restriction at high b values central dark area on DWI may represent fibrosis and necrosis 7this appearance, although not specific and only seen in less than 50% of cases, helps in distinguishing the mass from a hepatocellular carcinoma T1 C+ (Primovist) pattern and intensity of enhancement has been associated with tumor differentiation and, therefore, prognosis 6 hypoenhancement reflects poor differentiation rim enhancement reflects intermediate differentiation diffuse enhancement reflects a well-differentiated tumor only rarely forms a tumor thrombus
References 1. Chung YE, Kim MJ, Park YN et-al. Varying appearances of cholangiocarcinoma: radiologic-pathologic correlation. Radiographics. 29 (3): 683-700. doi:10.1148/rg.293085729 - Pubmed citation 2. Han JK, Choi BI, Kim AY et-al. Cholangiocarcinoma: pictorial essay of CT and cholangiographic findings. Radiographics. 22 (1): 173-87. Radiographics (full text) - Pubmed citation 3. Vilgrain V. Staging cholangiocarcinoma by imaging studies. HPB (Oxford). 2008;10 (2): 106-9. doi:10.1080/13651820801992617 - Free text at pubmed - Pubmed citation
Findings
evidence of illdefined T2 heterointense lesion with focally dilated intrahepatic biliary radicles noted in segment 7/8 of right lobe of liver , with subtle capsular retraction , which on contrast administration shows delayed enhancement
Discussion
Mass-forming intrahepatic cholangiocarcinomas (MF-ICC), also referred as peripheral cholangiocarcinomas, comprise one of the three recognized growth patterns of intrahepatic cholangiocarcinomas. On imaging, these tumors usually present as large and relatively well-defined hepatic masses with lobulated margins and showing peripheral rim enhancement. They are often associated with peripheral biliary dilatation. Epidemiology Mass-forming intrahepatic cholangiocarcinomas are associated with chronic liver diseases, including viral hepatitis . Clinical presentation These tumors tend to present late as larger masses as they rarely cause symptoms when smaller, early in their natural history Pathology The mass-forming subtype is the most common among the intrahepatic cholangiocarcinomas General morphological features that commonly guide radiologists to the diagnosis of mass-forming intrahepatic cholangiocarcinoma are the associated capsular retraction and distal bile duct dilatation. The enhancement pattern seen on post-contrast dynamic images can be quite variable, depending on tumor size and degree of differentiation. Be aware that enhancement features of mass-forming intrahepatic cholangiocarcinoma and hepatocellular carcinomas can overlap when tumors are smaller than 3 cm and in cirrhotic livers CT Mass-forming cholangiocarcinomas are relatively well-defined and markedly hypodense on the non-contrast studies. On dynamic post-contrast scans: there is minor peripheral rim enhancement during both the arterial and portal venous phases arterial enhancement has been associated with better prognosis 6 the central part of the tumor usually does not enhance during the early phases, but frequently show gradual centripetal prolonged enhancement at delayed-phases 1,2,4 rate and extent of enhancement depend on the degree of central fibrosis 1 The bile ducts distal to the mass are typically dilated. Again, capsular retraction may be evident and is highly suggestive of this etiology. Lobar or segmental hepatic atrophy is usually associated with vascular invasion 3. Although narrowing of the portal veins (or less frequently, hepatic veins) is seen, unlike hepatocellular carcinoma, cholangiocarciMRIT1: hypointense 7 T2: hyperintense 7 DWI: target sign of diffusion restriction at high b values central dark area on DWI may represent fibrosis and necrosis 7this appearance, although not specific and only seen in less than 50% of cases, helps in distinguishing the mass from a hepatocellular carcinoma T1 C+ (Primovist) pattern and intensity of enhancement has been associated with tumor differentiation and, therefore, prognosis 6 hypoenhancement reflects poor differentiation rim enhancement reflects intermediate differentiation diffuse enhancement reflects a well-differentiated tumor only rarely forms a tumor thrombus
References 1. Chung YE, Kim MJ, Park YN et-al. Varying appearances of cholangiocarcinoma: radiologic-pathologic correlation. Radiographics. 29 (3): 683-700. doi:10.1148/rg.293085729 - Pubmed citation 2. Han JK, Choi BI, Kim AY et-al. Cholangiocarcinoma: pictorial essay of CT and cholangiographic findings. Radiographics. 22 (1): 173-87. Radiographics (full text) - Pubmed citation 3. Vilgrain V. Staging cholangiocarcinoma by imaging studies. HPB (Oxford). 2008;10 (2): 106-9. doi:10.1080/13651820801992617 - Free text at pubmed - Pubmed citation
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!