Interesting ImagesRight Atrial Intimal Sarcoma on 18F-FDG PET/CTJanssen, Nick MD∗; Verheyen, Jef MD†; Albert, Adrien MD‡Author Information From the ∗Faculty of Medicine, University of Antwerp, Edegem †Cardiology Department, Klina, Brasschaat ‡Nuclear Medicine Department, University Hospital Antwerp, Edegem, Belgium. Received for publication August 28, 2019; revision accepted March 6, 2020. Conflicts of interest and sources of funding: none declared. Transthoracic cardiac ultrasound showed an incidental finding of an endocardial mass in the right atrium, which presented with a high SUVmean and SUVmax on the 18F-FDG PET/CT, suggesting a malignant process. Correspondence to: Adrien Albert MD, Wilrijkstraat 10, 2650 Edegem, Belgium. E-mail: Adrien.email@example.com. Clinical Nuclear Medicine: July 2020 - Volume 45 - Issue 7 - p e307-e308 doi: 10.1097/RLU.0000000000003051 Buy Metrics Abstract A right atrial mass was discovered with transthoracic cardiac ultrasound in a complaint-free, 81-year-old man at his yearly cardiological checkup. Further investigation of the mass with transesophageal cardiac ultrasound showed a well-defined nodular mass of approximately 3 × 3 cm, in close proximity to the posterior wall of the right atrium. The patient underwent an 18F-FDG PET/CT, which showed a right atrial mass with very high FDG uptake, suggesting a malignant process. The mass was surgically removed, and anatomopathological assessment revealed an intimal sarcoma, which is a very malignant tumor and an extremely rare occurrence at this location. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.