FDG PET/CT Combined With 3D CT Reconstruction in Diagnosing Inflammatory Granuloma Secondary to Fish Bone Perforation of the Ascending Colon.

A 71-year-old woman with a 5-week history of right-sided abdominal pain was initially suspected of hepatobiliary disorders. Upper abdominal ultrasound and MRI revealed unremarkable hepatobiliary findings. Although no hepatobiliary lesions were identified, MRI incidentally detected an ascending colon mass highly suspicious for malignancy. The patient underwent FDG PET/CT for differential diagnosis and preoperative staging. PET/CT with 3D CT reconstruction demonstrated a linear hyperdense foreign body within the ascending colon wall, causing focal bowel wall thickening with intense FDG avidity. These imaging findings were consistent with a foreign body-induced inflammatory granuloma, a diagnosis ultimately confirmed by colonoscopy and biopsy.