Abstract
A 73-year-old man diagnosed with acute pancreatitis underwent total colonoscopy for colorectal screening. A IIa+IIc lesion was detected in the cecum. Type III L pit with serration and type II open pit patterns were observed on the protruded part, which was diagnosed as a mixed serrated polyp (SSA/P and TSA). The pit pattern of the depressed floor was an invasive pattern (invasion to deep submucosa : SM). The patient strongly wished endoscopic submucosal dissection despite our suggestion of colectomy. Pathological diagnosis was well and focal moderately differentiated adenocarcinoma with a mixed serrated polyp. Depth of invasion was SM (1,900μm). Lymphatic vessel invasion was identified by D2-40. Thus, colectomy was performed later. We assumed cancer pathogenesis of this lesion with mucin core protein and gene expression profiles.
