Aneurismal type of colorectal cancer: imaging characteristics of gastrointestinal endoscopy, computed tomography and magnetic resonance imaging.

Background/aims: Only a few studies have investigated aneurismal large-intestinal malignant diseases. The present study reported five cases of aneurismal colon cancer that were experienced over 20 years. The present study aims to define the pathological and diagnostic imaging characteristics of aneurismal colon cancer.

Methodology: A case series from a retrospective review of large-intestinal malignant tumors at Saga Medical School, Japan. Barium enema was performed in 876 patients with large-intestinal advanced cancer, which included five with aneurismal-type cancer.

Results: The characteristics of the 5 cases were as follows: (i) pathological findings were poorly differentiated adenocarcinoma without desmoplastic change or mucinous adenocarcinoma; (ii) a typical aneurismal type revealed by barium enema had a low elevated tumor edge without stenosis upon endoscopic examination; (iii) computed tomography showed low attenuation without enhancement of contrast material; and (iv) magnetic resonance imaging indicated high intensity in the T2-weighted images of mucinous adenocarcinoma.

Conclusion: We revealed 5 cases of aneurismal colon cancer, which had characteristic pathological findings and diagnostic imaging, and poor prognosis.