sarcomatous changes occur in both hepatocellular carcinomas ( hcc ) and cholangiocarcinomas ( ccc ) . sarcomatoid changes may affect the imaging findings , thus the unique imaging characteristics of both hcc and ccc no longer exist . in the literature , hcc with sarcomatous changes however , there are only a few reports of sarcomatoid cholangiocarcinomas ( s - ccc ) without cross - sectional imaging findings . in this report , we present the computed tomography ( ct ) and magnetic resonance imaging ( mri ) findings of an intrahepatic sarcomatoid cholangiocarcinoma . a 48-year - old - man was admitted to our clinic with occasional left upper quadrant pain and fatigue . in his past medical history , he had a laparoscopic cholecystectomy operation 9 years previously . in his physical examination , left upper quadrant pain was noted that was aggrevated with palpation . abnormal laboratory findings included : total bilirubin , 1.4  mg / dl ( normal , < 1.2  mg / dl ) , direct bilirubin , 0.6  mg / dl ( normal , < 0.4  mg / dl ) , alkaline phosphatases , 224  iu / l ( normal , 44155 iu / l ) , glutamic oxaloacetate transaminase , 45  u / dl ( normal 1030  u / dl ) , glutamic pyruvic transaminase , 152  u / dl ( normal 727  u / dl ) , gamma - glutamyl transferase , 297  u / dl ( normal , 1049  u / dl ) , carbohydrate antigen 19 - 9 , 39  u / ml ( normal , < 30  u / ml ) . abdominal ultrasonography examination of the patient revealed a heterogeneous hypoechoic mass in the left liver lobe . both ct and mri of the upper abdomen were performed including magnetic resonance cholangiopancreatography ( mrcp ) . ct was performed on a 64-slice ct scanner ( somatom sensation ; siemens , erlangen , germany ) without contrast , in arterial and portal venous contrast enhancement phases . mri was performed on a 1.5-t scanner ( intera , philips medical systems , best , the netherlands ) . the standard upper abdomen mri protocol consisted of the following imaging sequences and parameters : t1-weighted spoiled gradient echo in dual phase ( repetition time ( tr ) , 140170  ms ; echo time ( te ) , 4.42.2  ms ; flip angle ( fa ) , 70 ) ; t1-weighted fat - saturated two - dimensional spoiled gradient echo ( tr , 160180  ms ; te , 4.3  ms ; fa , 70 ) ; and t2-weighted fat - saturated echo train fast spin echo ( tr , 8  ms ; te , 80  ms ) . all images were obtained in the axial plane with 6-mm section thickness and 160 to 190    256 matrix with a sensitivity encoding factor of 2 . mrcp images were obtained using two - dimensional breath - hold t2-weighted fat - saturated single - shot fast spin echo images ( tr , 8  ms ; te , 1200  ms ) with a slab thickness of 3050  mm in 12 paracoronal planes comprising an angle of 360. for the acquisition of each separate plane , patients held their breath for 5  s. gadolinium diethyltriaminepentaacetic acid ( magnevist ; schering , berlin , germany ) was injected at a dose of 0.1  mmol / kg of body weight as a bolus injection at 2  ml / s using a power injector ( medrad , indianola , pa ) . images were acquired at 18  s ( arterial - dominant phase ) , 45  s ( portal venous phase ) , and 90  s ( late venous phase ) after contrast administration . for serial contrast - enhanced images , a t1-weighted fat - saturated two - dimensional spoiled gradient echo sequence was used . on the upper abdomen ct examination ; a 13    10    7  cm heterogeneous hypodense irregular - shaped mass , which completely occupied segments 2 and 3 of the liver and partially located in segment 4 of the liver , extending to the liver hilus and causing lobulation of liver , was seen ( fig . the lesion was hypointense relative to the liver ; on t2-weighted images , it was heterogeneous and slightly hyperintense and more hyperintense areas were seen in the central region of the lesion . also , on t2-weighted images , there was a slightly hypointense area at the anterior - superior part of the lesion , which caused irregular retraction of the liver capsule that was evaluated as scar tissue ( fig . 2a , b ) . on dynamic contrast - enhanced ct and mri images , the lesion showed peripheral enhancement on the arterial phase and contrast enhancement in a progressive manner from the periphery to the centre on the venous phases . irregular - shaped areas in the centre of the lesion that showed no contrast enhancement in late phases were evaluated as necrotic changes . in addition , at the liver hilus adjacent to this mass , satellite nodules measuring approximately 4    2.5  cm and 3    2  cm were seen . multiple lymph nodes were seen with the largest measuring 22    12  mm . on mrcp images , intrahepatic bile duct dilatation due to compression of bile ducts secondary to the main mass and satellite lesions were seen ( fig . 4a , b ) . 
 figure 1intrahepatic cholangiocarcinoma showing sarcomatous transformation in the left liver lobe . ( a ) on non - contrast ct , the tumour presents as a heterogeneous hypodense mass ( arrow heads ) . ( b ) portal venous phase ct reveals contrast enhancement of the tumour mass except the necrotic areas in the centre . medial to the main tumour mass there is a more hypodense satellite tumour ( black arrows ) , which demonstrates slight contrast enhancement on contrast - enhanced images . note the lymph nodes at the preaortic and perigastric regions ( white arrow ) . 
 figure 2t2-weighted axial ( a ) and coronal ( b ) mr images . the tumour in the left liver lobe causes contour bulging and is heterogeneously hyperintense . in the central region of the mass , there are irregular more hyperintense areas consistent with necrotic changes ( * ) and in the anterior - superior part of the mass , a slightly hypointense area is seen to cause retraction of the liver capsule consistent with scar ( long arrows ) . the axial image demonstrates a more hyperintense satellite nodule adjacent to the medial part of the tumour , close to the central bile duct and causing compression ( short arrow ) . s , stomach . 
 figure 3axial t1-weighted non - contrast ( a ) , dynamic contrast - enhanced t1-weighted fat - saturated arterial ( b ) , portal venous ( c ) and late venous phase ( d ) mr images . non - contrast t1-weighted image demonstrates heterogeneous hypointense tumour ; satellite nodule medial to the main tumour is also hypointense ( arrow heads ) . dynamic contrast - enhanced t1-weighted images show tumour tissue ( arrows ) ; at later phases , progressive contrast enhancement is seen from periphery to central . on late venous phases , the central region of the tumour shows no contrast enhancement consistent with necrotic changes ( d ) . the satellite nodule shows less contrast enhancement than the main tumour on all phases ( arrow heads ) . figure 4mrcp images ( a , b ) show tumour tissue compressing the bile ducts ( long arrows ) extrinsically and therefore causing bile duct dilatation ( arrow heads ) . the diameter of the common bile duct and ductus pancreaticus is normal ( short arrow ) . ( a ) on non - contrast ct , the tumour presents as a heterogeneous hypodense mass ( arrow heads ) . ( b ) portal venous phase ct reveals contrast enhancement of the tumour mass except the necrotic areas in the centre . medial to the main tumour mass there is a more hypodense satellite tumour ( black arrows ) , which demonstrates slight contrast enhancement on contrast - enhanced images . note the lymph nodes at the preaortic and perigastric regions ( white arrow ) . the tumour in the left liver lobe causes contour bulging and is heterogeneously hyperintense . in the central region of the mass , there are irregular more hyperintense areas consistent with necrotic changes ( * ) and in the anterior - superior part of the mass , a slightly hypointense area is seen to cause retraction of the liver capsule consistent with scar ( long arrows ) . the axial image demonstrates a more hyperintense satellite nodule adjacent to the medial part of the tumour , close to the central bile duct and causing compression ( short arrow ) . axial t1-weighted non - contrast ( a ) , dynamic contrast - enhanced t1-weighted fat - saturated arterial ( b ) , portal venous ( c ) and late venous phase ( d ) mr images . non - contrast t1-weighted image demonstrates heterogeneous hypointense tumour ; satellite nodule medial to the main tumour is also hypointense ( arrow heads ) . dynamic contrast - enhanced t1-weighted images show tumour tissue ( arrows ) ; at later phases , progressive contrast enhancement is seen from periphery to central . on late venous phases , the central region of the tumour shows no contrast enhancement consistent with necrotic changes ( d ) . the satellite nodule shows less contrast enhancement than the main tumour on all phases ( arrow heads ) . mrcp images ( a , b ) show tumour tissue compressing the bile ducts ( long arrows ) extrinsically and therefore causing bile duct dilatation ( arrow heads ) . the diameter of the common bile duct and ductus pancreaticus is normal ( short arrow ) . * , renal cysts . left hemihepatectomy and lymphadenectomy was performed . there were no malignant cells at the surgical margins or in the hyperplastic lymph nodes . the patient received adjuvant oral chemotherapy for 6 months after the operation . on follow - up , mediastinal metastasis was suspected on thorax positron emission tomography / ct imaging at 12 months and thoracoscopic mediastinal tumour resection was performed that revealed a metastatic tumour with the same histopathology as the primary site . this feature is an indicator of sarcomatous transformation in a neoplasm of epithelial origin . in the literature , cholangiocarcinomas with sarcomatous transformation have been reported as mixed echoic masses on ultrasonography in some studies ; whereas in other studies they have been reported as heterogeneous hypoechoic masses on ultrasonography . in our case , in a few previously reported cases , the tumour showed hypointensity relative to liver parenchyma on t1-weighted images and hyperintensity relative to liver parenchyma on t2-weighted images . in some reports , mixed signal intensity of the mass was present on both t1- and t2-weighted images . on dynamic contrast - enhanced ct and mri , peripheral contrast enhancement , frequently seen in the arterial phase , the portal venous phase and the late venous phase with a progressive contrast enhancement pattern from the periphery to the centre was reported . this finding is in agreement with the contrast enhancement pattern seen in classic cholangiocarcinomas . in 3 cases reported in the literature in which angiography was performed , therefore , the typical contrast enhancement pattern of the sarcomatous component in cholangiocarcinomas with sarcomatous transformation is not yet known . in an analytical study covering a 15-year period , 4 cases out of 7 patients with cholangiocarcinoma with sarcomatous transformation , a satellite nodule was present , as observed in our case . the high incidence of satellite nodules in cholangiocarcinomas with sarcomatous transformation suggest a relationship between them . in another case study of cholangiocarcinoma with sarcomatous transformation and presenting with multiple satellite nodules , it was assumed that the more rapid growth and spread of sarcomatous elements compared with carcinomatous elements may be the cause . in our case , scar tissue was observed within the lesion , which may be considered in the differential diagnosis with other central scar - containing lesions such as fibrolameller hcc . despite these findings , imaging findings that may be helpful for comparison between cholangiocarcinomas with sarcomatous transformation and intrahepatic tumours a satellite nodule of the tumour and mixed internal signal intensities on mri were distinguishing features of the lesion .
abstractcomputed tomography ( ct ) and magnetic resonance imaging ( mri ) findings for a case of intrahepatic sarcomatoid cholangiocarcinoma is presented . 
 a 48-year - old man with upper abdominal pain underwent contrast - enhanced ct and mri . 
 a 13    10    7  cm mass was seen in the left liver lobe , which had hypodense internal architecture on ct and mixed signal intensities on both t1- and t2-weighted images with an overwhelmingly hypointense signal on t1-weighted images and a hyperintense signal on t2-weighted images . 
 the lesion had heterogeneous enhancement on both ct and mri . 
 a satellite nodule with the same imaging features was distinctive for the lesion .