Pseudoaneurysm of common iliac artery mimicking colonic metastasis on double-contrast barium enema.

We describe a patient with a pseudoaneurysm of the right common iliac artery that on a double-contrast barium enema mimicked the appearance of metastatic tumor involving the sigmoid colon, including a mass effect and spiculated, tethered mucosal folds. In the appropriate clinical setting, computed tomography, magnetic resonance imaging, and aortography help to distinguish a pseudoaneurysm from metastatic tumor involving the bowel.