Absence of the Right Common Iliac Vein with the Right Internal Iliac Vein Arising from the Left Common Iliac Vein: Case Report

The common iliac vein arises from the internal and external iliac veins and drains into the inferior vena cava, bilaterally. Historically, many anatomical variants of the common iliac vein have been studied. To our knowledge, we discuss a unique specimen, which presents with an absent right common iliac vein and a right internal iliac vein draining into the contralateral common iliac vein. It is important that we understand the anatomic variations of the pelvic venous system to prevent iatrogenic injury to patients or misdiagnosis.