Although ¹⁸F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) is a powerful tool for detecting the recurrence of colorectal cancer, FDG uptake is not tumor specific. Herein, we report a case of a 65-year- old man who underwent emergency colectomy for perforation of colon cancer. FDG-PET/CT after surgery showed 2 tumors that were difficult to differentiate from peritoneal metastases with invasion to the spleen. Splenectomy was performed, and the histopathology revealed that the tumors in fact were abscesses. This is a clinically thought-provoking case that showed the difficulty of the differential diagnosis between early recurrence after emergent surgery of colorectal cancer and the postoperative changes.