Intertumoral Heterogeneity of 18F-FDG and 68Ga-PSMA Uptake in Prostate Cancer Pulmonary Metastases.

We present a case of a 61-year-old man with history of prostate cancer and rising PSA levels referred for restaging. Ga-68-PSMA-11 PET/CT identified 2 lung nodules with low and moderate PSMA uptake. Subsequent F-18-FDG PET/CT showed high hypermetabolism in the nodule with low PSMA uptake, and low hypermetabolism in the nodule with moderate PSMA uptake. The isolated pulmonary findings and metabolic appearance is an atypical presentation of prostate cancer metastases and raised concern for a second primary malignancy. Fine-needle aspiration of the F-18-FDG active lung nodule confirmed metastatic prostatic adenocarcinoma that subsequently responded to androgen deprivation therapy and abiraterone acetate.