Colorectal carcinomas: diagnosis and preoperative staging by hydrocolonic sonography.

BACKGROUND: The aim of this study was to determine the sensitivity, specificity, and predictive value of hydrocolonic sonography (HS) in the detection and preoperative staging of colonic carcinomas. METHODS: One hundred four patients referred to our department for colorectal disease were examined in a prospective study with conventional transabdominal sonography followed by HS and other well-established means for detection of colorectal cancer. In all diagnosed colorectal carcinomas, surgical resection and histologic examination were carried out, and the histologically confirmed tumor stage was then compared with the stage predicted by HS. RESULTS: HS staged and made a correct diagnosis of carcinoma in 39 of 40 patients, with a sensitivity of 97.5% and a specificity of 98%. Positive predictability was 97.5% and negative predictability 98%. In the evaluation of cancer depth invasion, HS staging was correct in all but one case, in which a T3 tumor was incorrectly judged to be T2. In the assessment of the presence or absence of peritumor metastatic lymph nodes, HS had a sensitivity of 50% and a specificity of 100%. CONCLUSIONS: HS allows the diagnosis and preoperative staging of colorectal carcinomas with high sensitivity, specificity, and predictive value. We highly recommend its preoperative use because of its definitive influence on surgical approach.