Divergent PET Tracer Avidity in Synchronous Sarcomatoid Carcinoma With Osteosarcomatous Differentiation and Adenocarcinoma of the Prostate: Insights From Dual-Tracer 68 Ga-PSMA and 18 F-FDG PET/CT Imaging.

A 76-year-old man with mildly elevated prostate-specific antigen (PSA, 5.44ng/mL) and a PI-RADS 5 lesion on multiparametric MRI underwent dual-tracer PET/CT. 68 Ga-PSMA PET/CT revealed focal intense uptake in one prostatic lobe, while 18 F-FDG PET/CT demonstrated avid uptake in the contralateral lobe. Histopathology confirmed synchronous high-grade prostatic adenocarcinoma (Gleason 9) and sarcomatoid carcinoma with osteosarcomatous differentiation. This discordant dual-tracer pattern highlights the complementary role of PSMA and FDG PET/CT in detecting molecularly divergent synchronous prostatic malignancies.