Endoscopic ultrasonography for diagnosis of submucosal invasion in early gastric cancer

Endoscopic ultrasonography (EUS) is considered to be useful for deciding th e treatment course for early gastric cancer. To determine reliable indicati ons suggesting submucosal tumor invasion, we retrospectively analyzed EUS i mages of the hyperechoic third layer, which corresponds to the submucosa. T he subjects enrolled in this study were 75 patients, with 78 gastric cancer s (diagnosed as mucosal cancer without ulcerous changes on endoscopy and as histologically differentiated adenocarcinoma on biopsy), who were also exa mined by EUS. We retrospectively classified EUS features of the third layer (submucosa) into five groups: (1) irregular narrowing, (2) budding sign, ( 3) multiple echo-free spots, (4) unclear, and (5) no changes. In endoscopic ally diagnosed gastric mucosal cancer, 16 of the 78 lesions were associated with histologic submucosal invasion. EUS features that were associated wit h a high incidence of histological submucosal tumor invasion were irregular narrowing (submucosal invasion, 60.0%) and the budding si,on (85.7%), and 90.9% of lesions with either of these features had submucosal invasion of t umors when tumorous changes in the third layer exceeded 1 mm in depth. Endo sonographic irregular narrowing and a budding sign of more than 1 mm in dep th in the third layer are useful for the diagnosis of submucosal invasion i n gastric cancers that are diagnosed as mucosal cancers without ulcerous ch ange on endoscopy.