MACROSCOPIC DESCRIPTION: "Colon": A piece of oedematous, congested sigmoid colon 100mm in length. Located 5mm from the presumed distal resection margin is a circumferential, stenosing fungating tumour 30mm in length. Cross sectioning shows early invasion into mesocolic fat. The mesocolic fat contains several lymph nodes up to 8mm. There is uncomplicated diverticular disease.

MICROSCOPIC DESCRIPTION: Sections show a moderately differentiated colonic adenocarcinoma invading through the full thickness of the wall. Tumour is present in serosal adhesions and lies less than 0.1mm from the serosal surface. There is lymphovascular invasion. Eight lymph nodes were identified; three contain metastatic tumour. The tumour is at least 6mm from the distal resection margin. There is a separate severely dysplastic tubulovillous adenoma as well as uncomplicated diverticular disease.

DIAGNOSIS: Sigmoid colectomy: Moderately differentiated colonic adenocarcinoma.