Primary coexisting adenocarcinoma of the colon and neuroendocrine tumor of the duodenum: A case report and review of the literature

Figure 1 Colonoscopy and enhanced total abdominal computed tomography. A-C: Computed tomography (CT) shows that the colon cancer near the hepatic flexure of the transverse colon invaded the serosal layer, with a maximum invasion depth of approximately 2 cm, with small mesenteric lymph node metastasis (orange triangles) to be ruled out; CT plain scan (A), CT enhanced scan (B), and CT venous phase of the mass (C), respectively; D: Colonoscopy shows an irregular mass with a diameter of > 2 cm located 70 cm from the anus.