F-18-Fluciclovine Uptake In Thymoma Demonstrated On Pet/Mri

A 68-year-old man with a history of prostate cancer post-primary treatment presented with rising prostate-specific antigen levels and was referred for F-fluciclovine PET/MRI to localize recurrent disease. PET/MRI revealed a solitary focus of uptake in a soft tissue nodule in the anterior mediastinum, which was resected and found to be a type B2 thymoma. F-fluciclovine uptake is mediated by amino acid transporters, primarily alanine-serine-cysteine transporter 2 and L-type amino acid transporter 1, previously demonstrated to be expressed on thymic carcinomas. This case highlights the possibility of overexpression of amino acid transporters in thymomas as well, rarely described before.