Abstract
In order to determine whether the choice of treatment selected according to endoscopic diagnosis was appropriate, we investigated 245 cases of submucosal (sm) invasive colorectal carcinoma diagnosed by endoscopy. The lesions were inspected macroscopically to estimate the depth of the invasion, which is a major factor in selecting treatment. The lesions were then treated either endoscopically or surgically, and the specimens were histologically examined to evaluate the diagnosis. Out of the 245 cases, 114 (46.5%) were treated endoscopically ; of these 47 (41.2%) cases required additional surgical resection. Surgical resection without endoscopic treatment was performed in 131 of 245 (53. 5%) cases. The depth invasion of the 131 surgically resected cases were 31 of 131 (23.7%) sm1, 80 of theses (61.1%) sm2 and 20 cases (15.2%) were sm3. The oversurgery cases were estimated about ten percent in surgical resection cases. The other sm1 lesions were resected surgically the size and location of the lesion caused because endoscopic resection difficulty. Endoscopy resulted in a correct diagnosis in 198 of 245 (80.8%) cases. We then considered the possible reasons appropriate treatment was not selected upon endoscopic examination in the 47 cases who required additional surgical resection. The mode of growth of the lesion seemed to be crucial suggesting that the polypoid type of sm early cancer which is easily resected endoscopically was most likely misdiagnosised by endoscopy due to its shape. In addition, distinguishing between sml and a shallow invasion of sm2 is challenging. All the lesions assigned to sm3 were accurately assigned to receive appropriate surgical treatment. The presence or absence of invasion into the lymphatic system or veins was not assessable by examing morphological changes by endoscopy.
