A rare case of synovial sarcoma identified by ¹⁸ F-FDG and ⁶⁸ Ga-DOTANOC PET/CT

Synovial sarcoma is a relatively rare subset of soft tissue sarcoma. A male patient with an anterior mediastinal mass and multiple pulmonary nodules underwent 18 F-FDG and 68 Ga-(1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid)-1-NaI 3 -octreotide ( 68 Ga-DOTANOC) PET/CT scans to evaluate glycometabolism and somatostatin receptor (SSTR) expression, initially suspected to be thymic neuroendocrine tumor. Increased metabolic activity was observed in all lesions, while only one pulmonary nodule showed high expression of SSTR. In addition, there was a giant mass on the patient's thigh with high FDG uptake and partially high SSTR expression. The final pathology confirmed metastatic synovial sarcoma by biopsy of the pulmonary nodule.