AJR 2007; 188:785-790.
Ko EY, Ha HK, Kim AY, Yoon KH, Yoo CS, Kim HC, Kim JC.
OBJECTIVE: The purpose of this study was to evaluate the CT findings that can help differentiate mucinous from nonmucinous colorectal carcinoma.
MATERIALS AND METHODS: CT scans of 86 patients with pathologically proven mucinous colorectal carcinoma*were analyzed, and 105 consecutive patients with nonmucinous colorectal carcinoma were also included as a control group. CT findings were compared between the two groups with regard to the bowel involvement patterns; patterns of contrast enhancement; and presence or absence of bowel obstruction, intratumoral calcification, pericolic fat infiltration, and local tumor extension to adjacent organs. Statistical analyses were performed using the Student's t test and Pearson's chi-square test.
RESULTS: Compared with nonmucinous carcinoma, mucinous carcinoma showed more severe (2.41 ±1.19 cm vs 1.94 ±0.92 cm) (p = 0.004) and more eccentric (22% vs 8%) (p = 0.025) bowel-wall thickening. Heterogeneous contrast enhancement was more common in mucinous than in nonmucinous carcinoma (83% vs 53%) (p = 0.001). Mucinous carcinoma showed more areas with hypoattenuation (p = 0.001), and the solid portion of mucinous carcinoma showed less enhancement than that of nonmucinous carcinoma (p = 0.001). Presence of intratumoral calcification was more frequent in mucinous carcinoma (21% vs 5%) (p = 0.001). Heterogeneous enhancement showed the highest sensitivity (82.6%) but moderate specificity (55.9%) in diagnosing mucinous carcinoma. Tumors with four or more CT findings with a statistically significant difference were mostly mucinous carcinoma, and the specificity was 87%.
CONCLUSION: CT is useful in the differentiation of mucinous from nonmucinous colorectal carcinoma.