Incidental Detection of Temporary Focal FDG Retention in the Spleen.

F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) is a valuable tool in discriminating malignancy from benign lesion. But because various false-positive results reduce the diagnostic specificity, nuclear medicine physicians should be familiar with possible false-positive cases. Although many cases of high FDG uptake mimicking malignancy have been reported, temporary FDG uptake of normal spleen has not been reported previously. We report herein a phenomenon of temporary intense focal FDG uptake of normal spleen without evidence of metastasis in a 46-year-old woman with a history of anal cancer. (Figs. 1 and 2)