Asymptomatic familial colon cancer with FDG-PET scanning for recurrent disease.

A 57-yr-old female was referred for screening colonoscopy because of a positive family history of colon cancer. A lobulated tumor mass was detected in the sigmoid colon. The resected specimen showed an invasive adenocarcinoma without lymph node involvement. Later colonoscopic evaluations and CT imaging failed to reveal definite evidence of recurrent disease but a late rising carcinoembryonic antigen level led to FDG-PET scanning and the detection of suspect lymph nodes in the retroperitoneum. Further histopathological and immunohistochemical evaluation of resected lymph nodes confirmed metastatic carcinoma from the primary colon carcinoma with extra-nodal spread. This case underscores the ongoing need for additional evidence-based studies on evolving imaging modalities used in the diagnosis and management of colonic cancer.