[Early detection with FDG-PET of colonic tumors in patients with another known tumor]

Patients with known tumors can have other tumors in unexpected places, the so-called synchronic or second primary cancers. In these patients, whole-body fluorodeoxyglucose positron emission tomography (FDG-PET) to study known tumors can identify other tumors that would escape notice if only the sites of known tumors were investigated. We present 3 patients in whom whole-body FDG-PET was requested to study known tumors: 2 lung cancers and one melanoma. FDG-PET localized the known lesions and revealed hypermetabolic uptake in the abdomen in all 3 patients. Endoscopic polypectomy and pathologic analysis were performed, revealing 2 colon cancers and a tubular adenoma with a high degree of focal atypia. Whole body FDG-PET is a highly useful technique in the early diagnosis of colorectal cancer, which in turn allows complete cure of patients with this disease.