Delayed perforation of colonic stent for malignant large bowel obstruction

Inoperable sigmoid colonic cancer. Stent inserted. Now very severe abdominal pain and bloating.

Metallic stent in the sigmoid colon.  The proximal end sits within the mural thickening (presumed to represent tumour) and its flared end has eroded thorughthrough the wall anteriorly producing surrounding soft tissue swelling and free gas bubbles.  This is best seen on the sagittal projection. 

Note the right hepatic lobe mass indicative of metastasis.