| Abstract: | Abstract: We studied a patient with a sigmoid colon carcinoma, which looked like a type IIc carcinoma when it was, in fact, an advanced carcinoma. This lesion was considered to have developed from an early carcinoma with a depressed appearance. A 79-year-old woman was admitted complaining of a small amount of rectal bleeding. A barium enema examination revealed a flat elevated lesion with converging folds. A colonoscopy revealed a slightly reddish lesion with a central depression 40～50 cm from the anal verge. A biopsy specimen revealed the features of a well differentiated adenocarcinoma. A sigmoidectomy with lymph node dissection was performed. The resected specimen showed a tumor which looked like a so-called type IIc advanced carcinoma, measuring 10×6 mm in size. This lesion was histologically diagnosed as being a well differentiated adenocarcinoma without any adenomatous component. The tumor showed a massive invasion into the submucosal layer and a slight invasion into the proper muscle layer. |
