Gastro-Intestinal Tract

Cholangiocarcinoma

Mohamed Zaitoun

Assistant Lecturer-Diagnostic Radiology Department , Zagazig University Hospitals

EgyptFINR (Fellowship of Interventional

Neuroradiology)-Switzerlandzaitoun82@gmail.com

Knowing as much as possible about your enemy precedes successful battle

and learning about the disease process precedes successful management

Cholangiocarcinoma1-Incidence2-Clinical Picture3-Location4-Growth Patterns5-Staging6-Radiographic Features

1-Incidence :-Is a malignant tumor arising from the biliary

tree and tends to have a poor prognosis and high morbidity

-It is the second most common primary hepatic tumor with intra-hepatic cholangiocarcinoma accounting for 10-20% of primary liver tumors

-Usually in the elderly (7th decade)

2-Clinical Picture :-Painless jaundice

3-Location :a) Perihilar : originates from epithelium of main

hepatic ducts or junction : Klatskin tumorb) Peripheral : originates from epithelium of

intralobular ducts (beyond second-order bile ducts)

63-year-old man with hilar cholangiocarcinoma, intercostal sonographic scan through common hepatic duct shows well-defined soft-tissue intraductal mass (white arrow) within dilated intrahepatic duct (black arrow), S8 = segment VIII

58-year-old man with hilar cholangiocarcinoma, subcostal oblique gray-scale sonographic scan through porta hepatis shows abrupt narrowing of right intrahepatic duct (black arrows) secondary to infiltrating tumor (white arrow)

58-year-old man with hilar cholangiocarcinoma. Contrast-enhanced CT scan shows tumor (white arrows) infiltrating right portal vein (black arrow)

Klatskin tumor in a 57-year-old man who presented with jaundice, weight loss, and abdominal pain, (a)  CT scan shows dilatation of the intrahepatic biliary radicals in both hepatic lobes (black arrows) with an abrupt cutoff at the hilum (white arrow) but no discernible mass, (b) Corresponding coronal minimum-intensity-projection image shows the dilated biliary tree and obstruction by a hilar cholangiocarcinoma (arrow)

Peripheral mass-forming cholangiocarcinoma in a 73-year-old woman, (a) Noncontrast CT shows an irregular hypoattenuating lesion in segments VII and VIII of the liver (arrows) with retraction of the posterior liver surface and atrophy of the right lobe, (b) On an arterial phase, the lesion is predominantly hypoattenuating with minimal peripheral enhancement posteriorly (arrow), (c) Delayed phase shows the lesion with peripheral enhancement (black arrows) and progressive enhancement posteriorly (white arrow), although the center of the lesion remains hypoattenuating (*)

4-Growth Patterns :-Cholangiocarcinoma is classified into :a) Mass-formingb) Periductal infiltratingc) Intraductal growth

a) Mass-forming :-Mass-forming cholangiocarcinoma is

characterized morphologically by a homogeneous mass with an irregular but well-defined margin and is frequently associated with dilatation of the biliary trees in the tumor periphery

-Vascular encasement by the tumor is also common, but grossly visible intravascular tumor thrombosis is rare

Mass-forming intrahepatic cholangiocarcinoma manifests as a round mass with a distinct border in the liver parenchyma

*US :-Manifests as a homogeneous mass with an

irregular but well-defined margin-A peripheral hypoechoic rim is seen in about 35%

of all tumors and consists of compressed liver parenchyma or proliferating tumor cells

-Tumors greater than 3 cm in size are usually hyperechoic, but tumors less than 3 cm are hypo- or isoechoic

Mass-forming peripheral cholangiocarcinomas, (a) Transabdominal US image obtained in a 73-year-old woman shows a hypoechoic lesion (arrows), (b) Transabdominal US image obtained in a 41-year-old man shows a hyperechoic lesion (arrows), (c) Transabdominal US image obtained in a 66-year-old woman shows a mixed-echogenicity lesion (arrowheads) with biliary dilatation (arrow)

*CT :-Homogeneous attenuation, irregular peripheral

enhancement with gradual centripetal enhancement, capsular retraction, the presence of satellite nodules, and vascular encasement without the formation of a grossly visible tumor thrombus

-Other common findings include the presence of hepatolithiasis associated with the ductal dilatation and obliteration of the portal vein, leading to atrophy of the involved segment

Typical features of mass-forming cholangiocarcinoma at CT, (a) Arterial phase CT scan shows a tumor with ragged rim enhancement at the periphery (arrow), (b) Axial portal venous phase CT scan shows gradual centripetal enhancement of the tumor with capsular retraction (black arrow), a satellite nodule is also seen (white arrow), (c) Three-minute delayed phase CT scan shows gradual centripetal enhancement with tumor encasement of the posterior branch of the right portal vein (arrowhead), encasement of a portal or hepatic vein without formation of a grossly visible tumor thrombus is one of the distinguishing features of cholangiocarcinoma as opposed to HCC

58-year-old woman with mass-forming intrahepatic cholangiocarcinoma, CT scan shows lobulated tumor with sharp but irregularly rolled margin in right hepatic lobe

57-year-old man with mass-forming intrahepatic cholangiocarcinomas. CT scan shows irregularly shaped mass with peripheral enhancement, note three small peritumoral satellite nodules (arrow)

*MRI :-The MR imaging features of mass-forming

cholangiocarcinoma are similar to its CT features-The mass shows an irregular margin with high signal

intensity at T2 and with low signal intensity at T1-Both the peripheral and the centripetal enhancement may

be more prominent at MR imaging than at CT-In certain cases, prominent central enhancement can be

seen on the equilibrium phase or delayed phase MR images, a finding that is similar to the enhancement pattern seen at contrast-enhanced CT, the area of the tumor with early enhancement and rapid washout indicates active growth, whereas the central area is composed mainly of loose connective tissue with an abundant intercellular matrix  

Typical MR imaging features of mass-forming cholangiocarcinoma, (a) Axial fat-suppressed T2 shows a high-signal-intensity lobulated mass in the right hepatic lobe (arrow), (b, c) Contrast-enhanced arterial phase (b) and equilibrium phase (c) T1 show irregular, ragged rim enhancement (arrows in b) with gradual centripetal enhancement (arrowheads in c)

b) Periductal infiltrating :-Periductal infiltrating cholangiocarcinoma is

characterized by growth along a dilated or narrowed bile duct without mass formation and manifests as an elongated, spiculated, or branchlike abnormality

*US :-Appears as a small, masslike lesion or diffuse bile

duct thickening with or without obliteration of the bile duct lumen depending on tumor extent 

Periductal infiltrating intrahepatic cholangiocarcinoma is characterized by tumor infiltration along the bile duct (arrow), it occasionally involves the surrounding blood vessels or hepatic parenchyma

*CT & MRI :-Diffuse periductal thickening and increased

enhancement due to tumor infiltration can be seen, with an abnormally dilated or irregularly narrowed duct and peripheral ductal dilatation

-This type of tumor is rare in intrahepatic cholangiocarcinoma, but most hilar cholangiocarcinomas are of this type

-In the periphery of the liver, a combination of the periductal and mass-forming types is more common than a purely periductal infiltrating lesion

Periductal infiltrating intrahepatic cholangiocarcinoma in a 54-year-old man, (a) CT scan shows segmental dilatation of the intrahepatic duct in segment III (B3) only, multiple filling defects representing intrahepatic duct stones are also noted, (b) CT scan obtained 1 cm inferior to a shows a low-attenuation mass anterior to the left portal vein (arrow)

55-year-old man with periductal-infiltrating intrahepatic and extrahepatic cholangiocarcinoma, CT scan obtained at portal venous phase shows left intrahepatic bile duct dilatation (curved arrow) and obliteration of bile ducts in right hepatic lobe and hepatic hilum. Ill-defined, branchlike, low-attenuating mass (straight arrows) represents periductal infiltrating intrahepatic cholangiocarcinoma

Periductal infiltrating hilar cholangiocarcinoma, Coronal T2 shows irregular ductal wall thickening along a narrowed hilar bile duct (arrow)

Periductal infiltrating cholangiocarcinoma, (a) Axial T2 shows a dilated peripheral intrahepatic duct with a slightly hyperintense lesion around the duct (arrow), (b) Contrast-enhanced equilibrium phase MR image shows periductal enhancement around the dilated intrahepatic duct (arrowheads)

c) Intraductal growth :-Imaging patterns include :(a) diffuse and marked ductectasia with a grossly

visible papillary mass(b) diffuse and marked ductectasia without a visible

mass(c) an intraductal polypoid mass within localized

ductal dilatation(d) intraductal castlike lesions within a mildly dilated

duct(e) a focal stricture-like lesion with mild proximal

ductal dilatation

Intraductal intrahepatic cholangiocarcinoma is characterized by papillary or granular growth within the bile duct lumen, it occasionally demonstrates superficial extension (right arrow) or forms a tumor thrombus in an obstructed duct (left arrow), more than one type of cholangiocarcinoma may manifest in a single patient, in such cases, all of the types involved should be recorded (eg, “periductal infiltrating + intraductal”)

-Intraductal cholangiocarcinoma may be classified as either :

(1) Macroscopic(2) Microscopic-Microscopic lesions may represent the early form

of typical cholangiocarcinoma, whereas macroscopic lesions may represent a distinct pathologic entity, macroscopic lesions manifest as either papillary or tubular polypoid lesions

(a) Diffuse and Marked Ductectasia with a Grossly Visible Papillary Mass :

-The most distinguishable imaging pattern of the first type of intraductal cholangiocarcinoma is diffuse ductal dilatation with multifocal superficial spreading papillary or plaquelike masses at CT or MR imaging

*US :-An intraductal polypoid lesion is echogenic

relative to the surrounding liver

*CT :-At precontrast CT, an intraductal mass appears

as a lesion within the dilated bile duct that is hypo- or isoattenuating relative to the surrounding liver

-After contrast medium administration, the intraductal tumor shows enhancement, this lesion is usually confined to the bile duct wall, so that the wall will appear intact at US and CT

-In some cases, only marked intrahepatic bile duct dilatation with no obstructive mass or stricture can be detected at imaging, these imaging findings can be explained on the basis of copious mucin production, because mucin is usually anechoic at US and appears isoattenuating relative to water at precontrast CT, it is hard to detect at US or CT

Intraductal papillary neoplasm of the biliary tract with marked mucin production, CT+C (a) and T2 (b) show a markedly dilated intrahepatic duct with mural nodules or irregular wall thickening (arrow)

(b) Diffuse and Marked Ductectasia without a Visible Mass :

-In the second pattern of intraductal cholangiocarcinoma, a diffuse and marked ductectasia is present as in the first pattern, but a grossly visible mass is not present at CT& MR imaging

-This is either because of the micropapillary nature of the tumor or because of the limited spatial resolution of the imaging modalities

CT+C shows diffuse ductal dilatation in the left hepatic lobe through the common bile duct, with no visible intraductal mass

(c) An Intraductal Polypoid Mass within Localized Ductal Dilatation :

-The third pattern of intraductal tumors manifests as localized ductal dilatation with an intraductal mass

-An intraductal papillary mass is also usually present, but mucin secretion is not remarkable, so that the distal ductal dilatation is not prominent

53-year-old man with intraductal growing intrahepatic cholangiocarcinoma, CT+C shows aneurysmally dilated left hepatic bile ducts containing multiple fungating tumors and fluid in between, peripheral bile ducts (arrow) are dilated

Intraductal papillary cholangiocarcinoma, MRCP shows an intraductal polypoid mass with localized ductal dilatation (arrow)

(d) Intraductal Castlike Lesions within a Mildly Dilated Duct :

-The fourth pattern is one of the most difficult forms to diagnose correctly at imaging

-It manifests as an area of mild ductal dilatation filled with intraductal soft-tissue material, which may show mild enhancement at CT or MR imaging

Intraductal cholangiocarcinoma, (a) CT scan shows a soft-tissue component filling a mildly dilated duct (arrow), (b) MRCP shows the mildly dilated duct with irregularities that mimic impacted stones (arrowheads)

(e) A Focal Stricture-like Lesion with Mild Proximal Ductal Dilatation :

-The last pattern of intraductal cholangiocarcinoma manifests as a focal stricture-like lesion with mild proximal ductal dilatation and no demonstrable mass

 Axial contrast-enhanced MR image show a focal stricture (arrow) with mild ductal dilatation

5-Staging : Bismuth-Corlette classification-Classification system for perihilar cholangiocarcinoma which is

based on the extent of ductal infiltration*Type I : Limited to the common hepatic duct below the level of the

confluence of the right and left hepatic ducts*Type II : Involves the confluence of the right and left hepatic ducts*Type IIIa : Type II + extends to the bifurcation of the right hepatic

duct*Type IIIb : Type II + extends to the bifurcation of the left hepatic

duct*Type IV : Extending to the bifurcations of both right and left

hepatic ducts OR multifocal involvement

Drawings illustrate the Bismuth-Corlette classification of perihilar cholangiocarcinomas, Type I involves the common hepatic duct (CHD), Type II, the CHD and the junction of the RHD and LHD, Type IIIA, the CHD, biliary junction, and RHD, Type IIIB, the CHD, biliary junction, and LHD and Type IV, the CHD and the biliary junction, with extension to both the RHD and LHD or a multifocal bile duct tumor

6-Radiographic Features :a) Dilated intrahepatic ductsb) Hilar lesionsc) Peripheral Lesionsd) CTe) MRCP

a) Dilated intrahepatic ducts with normal extrahepatic ducts

b) Hilar lesions :-Central obstruction-Lesions are usually infiltrative so that a

mass is not usually apparent-Encasement of portal veins causes irregular

enhancement by CT

Infiltrative hilar cholangiocarcinoma in a 59-year-old woman with progressive jaundice, (a) Arterial-phase CT shows a well-enhancing, thickened bile duct wall (arrows) at the hepatic hilar level, (b) Cholangiogram shows complete obstruction at the hepatic hilar level and severe strictures (arrows) that involve both hepatic ducts

Klatskin Tumor: arterial and portal venous phase

c) Peripheral Lesions :-May present as a focal mass or be diffusely

infiltrative-Retain contrast materials on delayed scans

(minor peripheral enhancement with gradual enhancement centrally)

-Occasionally invade veins

Peripheral cholangiocarcinoma, (a) Arterial-phase CT scan shows a low-attenuation mass (marker) with rim enhancement, note the dilatation of the peripheral intrahepatic ducts (arrows), (b) On a portal-phase CT scan, the mass looks smaller because the central portion is now more enhanced, the rim enhancement seen in a is partially washed out, capsular retraction is also noted (arrow)

d) CT :The key findings to look for are >>1-Delayed enhancement 2-Peripheral biliary dilatation 3-Capsular contractione) MRCP :1-Short annular constricting lesion , 75%2-Long stricture , 10 %3-Intraluminal polypoid mass , 5 %

Delayed Enhancement

Capsular Retraction

67-year-old man with Klatskin tumor, MRCP shows tumor involvement of primary confluence of bile duct (arrow)