Absence of Inferior Mesenteric Vein: A Case Report

We report a rare case of absence of inferior mesenteric vein (IMV) with collateral venous drainage via left and middle marginal veins of colon. The superior rectal vein, sigmoid colic vein and left colic vein drain into left and middle marginal veins of colon and then drain into portal venous system. Absence of IMV was demonstrated by contrast-enhanced computed tomography (CT) in a patient with rectal cancer.