18F-FDG PET/CT and 68Ga-FAPI-04 PET/CT Findings of Abdominal Leiomyosarcoma.

A 56-year-old woman presented with abdominal pain and vomiting. Her abdominal CT revealed an retroperitoneal mass in the left upper quadrant of the abdomen. 18F-FDG PET/CT performed for metabolic characterization showed low to moderate heterogenous FDG uptake. 68Ga-fibroblast activation protein-specific inhibitor (FAPI)-04 PET/CT performed according to a research carried out in our department showed high heterogenous radiopharmaceutical uptake. The patient was diagnosed with leiomyosarcoma after R0 tumor resection. This case showed that 68Ga-FAPI-04 PET/CT could be a promising radiopharmaceutical in the evaluation of leiomyosarcomas.