Unusual Case of Diffuse Penile Metastasis of Prostate Cancer on 68Ga PSMA PET/CT Imaging and 177Lu PSMA Posttherapy Scintigraphy.

An 85-year-old man with prostate cancer for metastatic workup underwent Gallium Prostate-Specific Membrane Antigen (Ga-PSMA) PET/CT (Ga-PSMA PET/CT), which revealed unusual tracer uptake in the shaft and glans of penis as well as multiple systemic metastases in liver, skeletal, and lymph nodes. The penile lesion was proved to be metastatic adenocarcinoma from prostate on fine needle aspiration cytology. The patient underwent Lutetium (Lu)-labeled PSMA radioligand therapy, which also revealed diffuse tracer uptake in the penile shaft as well as other metastatic sites.