Heterogeneous Uptake of 18F-FDG and 68Ga-PSMA-11 in Hepatocellular Carcinoma

We present the case of an 87-year-old man with a history of melanoma metastatic to the lungs found to have an FDG-negative liver lesion that was initially thought to be benign. Follow-up CT revealed growth of the liver lesion despite excellent response to nivolumab therapy of the pulmonary melanoma metastases. Biopsy of the lesion confirmed primary hepatocellular carcinoma. Follow-up F-FDG PET/CT showed minimal FDG uptake, slightly above liver background, and subsequent Ga-PSMA-11 PET/MR showed focal, intense uptake of radiotracer in a different region of the tumor. These imaging findings support intratumor metabolic heterogeneity with radiotracer uptake in different tumor locations.