Clinical usefulness of endoscopic ultrasonography for the evaluation of ulcerative colitis-associated tumors

AIM: To evaluate the clinical usefulness of endoscopic ultrasonography (EUS) for the diagnosis of the invasion depth of ulcerative colitis-associated tumors. METHODS: The study group comprised 13 patients with 16 ulcerative colitis (UC)-associated tumors for which the depth of invasion was preoperatively estimated by EUS. The lesions were then resected endoscopically or by surgical colectomy and were examined histopathologically. The mean age of the subjects was 48.2 +/- 17.1 years, and the mean duration of UC was 15.8 +/- 8.3 years. Two lesions were treated by endoscopic resection and the other 14 lesions by surgical colectomy. The depth of invasion of UC-associated tumors was estimated by EUS using an ultrasonic probe and was evaluated on the basis of the deepest layer with narrowing or rupture of the colonic wall. RESULTS: The diagnosis of UC-associated tumors by EUS was carcinoma for 13 lesions and dysplasia for 3 lesions. The invasion depth of the carcinomas was intramucosal for 8 lesions, submucosal for 2, the muscularis propria for 2, and subserosal for 1. Eleven (69%) of the 16 lesions arose in the rectum. The macroscopic appearance was the laterally spreading tumor-non-granular type for 4 lesions, sessile type for 4, laterally spreading tumor-granular type for 3, semipedunculated type (Isp) for 2, type 1 for 2, and type 3 for 1. The depth of invasion was correctly estimated by EUS for 15 lesions (94%) but was misdiagnosed as intramucosal for 1 carcinoma with high-grade submucosal invasion. The 2 lesions treated by endoscopic resection were intramucosal carcinoma and dysplasia, and both were diagnosed as intramucosal lesions by EUS. CONCLUSION: EUS provides a good estimation of the invasion depth of UC-associated tumors and may thus facilitate the selection of treatment.