A 67-year-old woman with a history of malignant melanoma in the right lower leg for 7 years without any known metastases was hospitalized for evaluation of severe left upper quadrant abdominal pain. Computed tomography of the abdomen revealed a suspected splenic mass. F-18 FDG PET/CT imaging showed a large photopenic area in the same region surrounded by a circular area of high FDG uptake. It could not be definitely differentiated between a splenic infarction and a necrotizing metastasis of malignant melanoma or other malignancies. Subsequent splenectomy revealed an infected splenic infarction.