Figure 4: (A,B): A 67-year-old man operated for rectosigmoid malignancy presented with rising tumor marker levels and underwent an FDG PET / CT study. The fusion FDG PET / CT image (A) reveals a tiny, but intense focus of FDG uptake (arrow) at the rectosigmoid anastomotic site. A contrast-enhanced CT scan of the abdomen and pelvis and colonoscopy, however, did not reveal recurrence; hence, the patient was kept under observation. A follow-up PET / CT study done after eight weeks (B) shows disease progression, by demonstrating increase in the extent and intensity of the FDG uptake, with the appearance of a soft tissue mass at the anastomotic site. A colonoscopic biopsy confirmed recurrence. Hyperdense surgical staples (arrowheads in A and B) mark the anastomotic site.