Abstract
A 46-year-old mal was admitted to our hospital for farther examination of positive fecal occult blood in stool. Colonoscopy revealed a rectal cancer like a+c lesion. Endoscopic ultrasonography showed that the cancerous lesion seemed to be limited to the mucosal layer, but a well-difined, round and low echoic lesion was detected in the submucosal layer. This low echoic lesion was diagnosed as lymph follicle by EUS and then, this lesion was diagnosed as mucosal cancer and resected endoscopically. Histopathology of the resected specimen revealed a mucosal cancer with lymph follicles in the submucosal layer. Generally it is difficult to distinguish lymph follicles in submucosal layer from submucosal invasion of cancer by EUS. However, the differentiation was possible in this case.
