Case 303:   Cholangiocarcinoma

Diagnostic Category:

Clinical Presentation:

56 year old man with abdominal pain.

US: With wedge shaped focal fatty sparing

Imaging Findings:

Ultrasound shows steatosis with biopsy proven small nodular cholangiocarcinoma (first image), and wedge shaped fat sparing peripherally (second image).
The sparing is a result of the blocked portalvenous sinuses, which are obstructed by the small mass. This portion of the liver is not exposed to portal venous blood and therefore did not undergo steatotic transformation.

Wedge shaped fat sparing can suggest the presence of a small mass, even before the mass self is identified, and should therefore always be further investigated.