A dilated epidural venous plexus (DEVP) is a rare cause of radiculopathy, back pain, cauda equina syndrome, and other neurological symptoms. This vascular mass can be secondary to inferior vena cava (IVC) obstruction, portal hypertension, vascular agenesis, and hypercoagulable states. Although rare, DEVP should be considered in the differential diagnosis for patients who present with lumbar radiculopathy. Here, we present two cases involving patients with lumbar DEVP. We present a literature review of the role of hypercoagulability, vascular anatomy, and IVC thrombosis in the development of DEVP. The first patient had a history of recurrent deep vein thrombosis (DVT) systemic lupus erythematosus (SLE), and antiphospholipid syndrome. The diagnosis of DEVP was determined after intraoperative biopsy. She reported symptom resolution at her six-month post-op appointment. The second patient developed DEVP associated with Klippel-Trenaunay Syndrome (KTS). She presented with back pain and leg weakness, was diagnosed via magnetic resonance imaging (MRI), and is currently being followed by neurosurgery. We believe this is the first case of KTS associated with DEVP. In summary, we propose that if a patient presents with an enhancing epidural lesion on MRI and neurological symptoms, DEVP should be considered in the differential diagnosis. Additionally, a search for IVC thrombosis should be performed as well as risk factors for venous hypertension and hypercoagulable states.Copyright © 2020 Elsevier Inc. All rights reserved.