A 45-year-old woman presented with a 6-week history of anorexia, diarrhoea and weight loss. Barium enema examination showed a stricturing lesion in the caecum consistent with the radiological features of a colonic carcinoma. A computed tomography scan of the abdomen confirmed the presence of circumferential mural thickening of the caecum, with extensive surrounding pericolic infiltration. There was no evidence of metastasis.

At laparotomy, there was a palpable caecal mass extending to the ileocaecal valve which was adherent to the right pelvic side wall and to the proximal transverse colon. An extended right hemicolectomy was performed.

The surgical specimen contained an annular mass in the caecum (fig 1), extending to the terminal ileum. …