Fig. 2From: Histological transformation to signet-ring cell carcinoma in a patient with clinically aggressive poorly differentiated adenocarcinoma of the ascending colon after response to chemotherapy plus cetuximab: a case reportColonoscopy findings. Colonoscopy revealed the anal side margin of the circumferential tumor on the hepatic flexure. Biopsy was taken from the tumor, and the tumor was diagnosed as PDA of the ascending colon using immunostaining to discriminate it from malignant lymphomaBack to article page