A Case of Well-differentiated Hepatocellular Carcinoma Identified on Gallium-68 Prostate-specific Membrane Antigen Positron Emission Tomography/Computed Tomography

Prostate-specific membrane antigen (PSMA) is a glycosylated type-II transmembrane protein highly expressed in certain tumor cells. To the best of our knowledge, this is the first case reported of an isolated well-differentiated hepatocellular carcinoma (HCC) strongly suspected on gallium-68 ((68)Ga)-PSMA positron emission tomography/computed tomography (PET/CT), which was not well characterized both on magnetic resonance imaging (MRI) liver with Primovist as well as fluorine-18 ((18)F)-choline PET/CT. Our patient had previous prostate cancer and previously was imaged using (18)F-choline PET/CT. The last scan showed an indeterminate segment VII hypodensity which was not significantly choline-avid. The lesion was initially stable on serial MRI scans but then showed growth from 1.0 to 1.5 cm. (68)Ga-PSMA PET/CT was performed. The lesion was intensely tracer-avid. This was surgically excised and histology confirmed the presence of well-differentiated HCC. Well-differentiated HCC can be optimally imaged using (68)Ga-PSMA PET/CT and further prospective studies are needed to look into the potential of this imaging modality.