DIAGNOSIS OF EARLY COLORECTAL TUMOR INVASION BY ENDOSCOPIC ULTRASONOGRAPHY (EUS)

WITH SPECIAL REFERENCE TO THE DETECTABILITY OF DEGREE OF 5UBMUCOSAL CARCINOMATOUS INFILTRATION

Abstract

EUS was attempted in 102 lesions with early colorectal tumor for the diagnosis of carcinomatous invasion. These lesions were histologically confirmed by surgical or endoscopic resection ; 44 with adenoma, 37 with mucosal carcinoma and 21 with sub-mucosal carcinoma. In these series, 44 lesions with adenoma were dealt as mucosal invasion, and 21 lesions with submucosal carcinoma were divided into three groups, sml, sm2, and sm3, according to the degree of carcinomatous infiltration within the submucosal layer. EUS diagnosis of tumor invasion were correct in 93 of 102 lesions (91%) ; 68 of 76 (89%) in protruded lesions and 25 of 26 (96%) in superficial lesions. Detection of the degree of submucosal infiltration with EUS was possible in 13 of 21(62%) lesions with submucosal carcinoma ; 7 of 14 (50%) in protruded lesions and 6 of 7 (86%) in superficial lesions. It provided a high accuracy rate in the lesions less than 7 mm in height. The most important factors in the EUS diagnosis of carcinoma invasion or submucosal carcinoma infiltration was the shape and height of the lesions. It is concluded that EUS is of great value for the detection of infiltration degree of submucosal carcinoma as well as for the diagnosis of early colorectal tumor invasion.