Food residue granuloma mimicking metastatic disease on FDG-PET/CT.

A 31-year-old woman presenting with acute abdomen underwent an emergency Hartmann's procedure for fecal peritonitis due to perforated adenocarcinoma of the left colon. Shortly after a 7-month course of adjuvant chemotherapy, follow-up contrast-enhanced CT showed multiple peritoneal and hepatic nodules, showing focal intense and homogeneous FDG uptake on FDG-PET/CT, highly suspected for recurrence of disease. Excisional biopsy of the nodules revealed foreign body granulomas made up of alimentary materials surrounded by a fibrous wall. We report a unique case of a false-positive finding secondary to food residues mimicking metastatic disease on FDG-PET in a patient with colon cancer.