Biliary Neoplasms

Question 1

Von Meyenburg complex

Answer 1

• Von Meyenburg complex (VMC) is a ductal plate malformation of the liver characterized by dilated interanastomosing bile duct structures in collagenized stroma
• Results from failure of involution of excess embryologic remnants
• Considered benign and requires no treatment
• Can also be associated with hepatic cysts and other ductal plate malformation diseases, such as polycystic kidney disease, Caroli disease, Caroli syndrome and congenital hepatic fibrosis

Micro:
* Small to medium sized, irregularly shaped bile ducts lined by bland cuboidal or flattened epithelium
* Glands typically more dilated / cystic than normal bile ducts with prominent intervening collagenous stroma
* Bile ducts may contain inspissated bile or eosinophilic debris
* Commonly subcapsular or located at or in the periphery of portal tracts
* Surrounding inflammatory cells may be present

IHC:
* CK 7
* CK 19

Question 2

Cholangiocarcinoma

Answer 2

• Intra-hepatic
• Extra-hepatic
• Hilar

Clincal Features:
* Arises/differentiates as bile duct epithelium
* Hilar tumours –> Klatskin
* Elevated serum CEA
* Generally poor prognosis

Intrahep origin:
* Stem cells residing in the canals of Hering
* Stem cells within peribiliary glands

Risk factors:
* Ulcerative colitis
* Primary sclerosing cholangitis
* Cirrhosis
* Alcohol
* Viral hep B and C
* Thorium dioxide (Thorotrast) exposure
* Clonorchis sinensis infestation (intrahep)
* Opisthorchis sinesis infestation (intrahep)
* Intrahepatic bile duct lithiasis

Macro:
Intrahepatic:
* grey-white
* tough
* finger-like extensions along bile-duct and lymphatics
* can be large
* often multifocal

Extrahepatic:
* Nodular/flat sclerotic lesions
* Deep penetration into bile duct wall
* Less commonly –> polypoid superficial lesions

Klatskin:
* Begins at hepatic duct junction
* Spreads along segments of biliary tree
* Large green liver with collapse of gallbladder and extrahepatic ducts in characteristic

Micro:
* usually well-differentiated, mucin-secreting adenocarcinomas
* abundant fibrous stroma
* typically do no show necrosis
* Increased NC ratio, prominent nucleoli
* Concentric layering of cellular stroma around neoplastic glands
* Spreads between hepatic plates (sinusoidal growth)n along ducts and nerves
* Stromal and perineural invasion

IHC:
* Mucicarmine and PAS with diastase (PAS-D) positive
* EMA, Keratins 7 and 19 positive
* Villin positive with brush-border accentuation
* CEA positive, lacks canalicular staining of HCC
* EGFR positive