Fig. 23.34 Carcinoid tumour: distal ileal involvement. This 80- minute follow-through film shows an abnormal distal ileum with mesentenic thickening, nodular masses invading the bowel wall and angulation and tethering of mucosal folds. These appearances are characteristic of carcinoid tumour and reflect invasion by the tumour with an extensive fibroblastic response. Metastatic carcinoma to the mesentery can cause a similar appearance.