We report a case of a 75-year-old man with concomitant metastatic prostate cancer and progressive follicular lymphoma and the utility of molecular imaging in differentiating these 2 conditions. F-FDG PET/CT can offer accurate staging in many cancers, although its role in prostate cancer is limited. The role of F-DCFPyL (PSMA) PET/CT in prostate cancer is evolving and has been demonstrated to have a higher sensitivity than conventional bone scan and CT scan. Together, FDG and PSMA PET/CT studies may offer a noninvasive approach to individually characterize concomitant malignancies, aiding optimization of management and follow-up.