Utility of Narrow-Band Imaging during Intraoperative Colonoscopy for Colon Tumor Localization: A Report of Two Cases

Accurate intraoperative localization of colonic tumors is essential to ensure appropriate resection margins, particularly in laparoscopic surgery where tactile feedback is limited. Intraoperative colonoscopy combined with narrow-band imaging (NBI) may facilitate precise delineation of tumor borders, but its clinical utility remains underreported.

We report 2 cases of cecal tumors in which intraoperative colonoscopy with NBI was employed to identify tumor margins and guide resection. The first case was a 79-year-old man with a positive fecal occult blood test, in whom colonoscopy revealed a 25-mm laterally spreading tumor (LST) in the cecum. During laparoscopic surgery, intraoperative colonoscopy with NBI clearly visualized the lesion, enabling cecal resection with negative histopathological margins. The second case was a 75-year-old woman referred for surgery following the detection of a 30-mm LST involving the appendiceal orifice. Intraoperative colonoscopy with NBI enabled accurate margin assessment, and the tumor was resected without residual disease. Histopathology confirmed tubulovillous adenoma with negative resection margins.

Intraoperative colonoscopy with NBI was effective for identifying tumor borders and ensuring adequate resection margins in both cases. This approach may be a valuable adjunct in selected patients undergoing laparoscopic colorectal surgery, particularly for tumors located in anatomically complex regions such as the cecum or appendiceal orifice.