Uneven haustra on CT colonography: a clue for the detection of transperitoneal invasion from gastric cancer.

Two patients with gastric carcinoma underwent CT colonography (CTC) for preoperative work-up. Although no obvious peritoneal nodules were seen on axial CT images, colonic wall deformities were noted on three-dimensional (3D) air images. Multiplanar-reformatted images revealed corresponding colonic wall thickening at the deformities, and in addition, dense cordlike structures connecting the primary gastric cancer and colonic wall thickening were also observed. In one patient, cordlike indurations consistent with peritoneal invasion were found to connect the primary gastric cancer, gastrocolic ligament, and transverse mesocolon during exploratory surgery, and in the other, colonic scars consistent with peritoneal invasion after chemotherapy were observed. These observations suggest that CTC could be of potential use for the differentiation of transperitoneal colonic invasion and gastric cancer.