Prostate-Specific Membrane Antigen PET/CT: Uptake in Lymph Nodes With Active Sarcoidosis.

We describe 2 cases of Ga-PSMA PET/CT in prostate cancer patients. Both cases demonstrated symmetrical bilateral involvement of mediastinal and hilar lymph nodes besides findings in relation with prostatic disease. In both cases, endobronchial ultrasound-guided biopsy showed that the involvement of the thoracic lymph nodes was caused by nonnecrotic granulomas compatible with sarcoidosis. The cases demonstrated that increased Ga-PSMA uptake can be seen in lymph nodes with active sarcoidosis, with images mimicking those well known from FDG PET/CT. Because of these findings, granulomatous disease has to be included in the differential diagnostic evaluation of patients with Ga-PSMA-positive lymph nodes.