Hypermetabolic Hepatic Adenoma

A hepatic adenoma is an uncommon benign liver lesion and is nearly always non-avid. 

On very rare occasion, a hepatic adenoma will present as an FDG-avid lesion on the PET portion of the exam.  

The finding of a hypermetabolic hepatic adenoma, however, is so uncommon that we do not include it in our reports in the differential diagnosis for an FDG-avid liver lesion.

The diagnosis, however, can be vaguely entertained (though biopsy will nearly always be required) when a hypermetabolic liver lesion is truly an unexpected/incidental finding — especially in a premenopausal woman on oral contraceptive pills.

Benign FDG-avid liver masses are so rare that any FDG-avid liver lesion should be considered malignant until proven otherwise.