FDG uptake in a catheter-related thrombus simulating relapse of lymphoma

FDG-PET imaging was performed because of suspected recurrence of lymphoma of the chest. There was an area of increased activity posterior to the left sternoclavicular joint, suspected of being a relapse. Workup showed a thrombus at the tip of a central venous line corresponding to the FDG uptake. This is explained by the inflammatory process involving and surrounding chronic thrombus. Focal activity in relation to the tip of a venous catheter is very likely to have a benign etiology. It is important to recognize this not to overdiagnose a malignancy. For a correct interpretation, it is necessary to know the patient's history and having access to current radiologic examinations.