Early colorectal cancer in a flat adenoma.

A 56-year-old man presented with intermittent rectal bleeding of six months' duration. Colonoscopy revealed three left colon polyps, one of which harbored adenocarcinoma. Endoscopic mucosal resection (band-assisted colonoscopic polypectomy) was successful. Endoscopic ultrasonography did not demonstrate any local or regional spread; however, abdominal computed tomography (CT) scan raised suspicion of an isolated metastasis to the liver. The patient's mother had recently died from metastatic colorectal cancer. When presented with the options of no surgery, postendoscopic mucosal resection, and CT-directed needle biopsy of the suspected isolated metastasis to the liver versus segmental resection of the flat adenoma site and wedge resection of the liver lesion for the maximum chance of a surgical cure, the patient opted for the surgical approach. Histopathology revealed no evidence of malignancy in the rectosigmoid colon, pericolonic lymph, or liver specimen. Awareness of increased risk of early cancer in flat adenomas with central depression is important because prompt recognition can lead to curative therapy.