52 year old man with mass on routine screening colonoscopy.
- Focal intense FDG uptake fusing to circumferential thickening of the descending colon.
- Focal intense FDG uptake fusing to the liver adjacent to the gallbladder fundus.
- Mild FDG activity in the right anterior 3rd and 4th ribs, in a pattern suggesting prior trauma.
Contrast-enhanced CT demonstrated a hypodense mass in the liver adjacent to the gallbladder fossa, and MRI showed a hypoenhancing mass which is slightly T2 hyperintense.
Colorectal cancer metastases to the liver are classically hypovascular when compared to the normal liver parenchyma.
Take a look at this hepatic arteriogram in a patient with large, untreated colorectal metastases:
Notice the large area of hypoenhancement in the right lobe after contrast injection.
Here is this patient’s MRI:
Despite this centrally hypoenhancing appearance, colon cancer metastases are usually very FDG avid (with the exception of mucinous tumors) and are one of the main indications for intra-arterial therapy including radioembolization with yttrium-90 microspheres.
Please see topic discussion on Y90 Radioembolization.