Changes

Cholangiocellular tumours include bile duct '''carcinomas''' and '''adenomas'''.  Bile duct carcinomas are the most common malignant hepatobillary tumours in cats and the second most frequent in dogs, with female animals possibly being predisposed.  Intra-hepatic carcinomas are more frequent in dogs but in cats, it is unclear whether extra-hepatic masses occur more frequently or whether intra- and extra-hepatic masses occur with equal frequency.

Cholangiocellular tumours include bile duct '''carcinomas''' and '''adenomas'''.  Bile duct carcinomas are the most common malignant hepatobillary tumours in cats and the second most frequent in dogs, with female animals possibly being predisposed.  Intra-hepatic carcinomas are more frequent in dogs but in cats, it is unclear whether extra-hepatic masses occur more frequently or whether intra- and extra-hepatic masses occur with equal frequency.

Bile duct carcinomas are aggressive and they often metastasise to distant sites.  In dogs, these metastases are most common in the regional lymph nodes and lungs but diffuse intra-peritoneal metastasis and carcinomatosis are more common in cats.  Bile duct adenomas (also known as biliary or hepatobiliary cystadenomas) are common in cats, particularly in males.  These tumours are generally insignificant unless they of sufficient size to compress surrounding soft tissue structures and cause [[Biliary Tract - Obstruction|biliary tract obstruction]].

Bile duct carcinomas are aggressive and they often metastasise to distant sites.  In dogs, these metastases are most common in the regional lymph nodes and lungs but diffuse intra-peritoneal metastasis and carcinomatosis are more common in cats.  Bile duct adenomas (also known as biliary or hepatobiliary cystadenomas) are common in cats, particularly in males.  These tumours are generally insignificant unless they of sufficient size to compress surrounding soft tissue structures and cause [[Biliary Tract Obstruction|biliary tract obstruction]].

===Carcinoids===

===Carcinoids===