A 32-year-old man with a history of bronchial asthma was referred for low back pain and bilateral femur pain. Vascular sonography revealed bilateral deep vein thrombosis (DVT) from the femoral veins to the popliteal veins. Computed tomography revealed hypoplasia of the inferior vena cava (IVC) and dilated lumbar veins, ascending lumbar veins, and azygos vein as collaterals. There was no evidence of malignant neoplasm. The results of the thrombophilia tests were within normal limits. Hypoplasia of the IVC is a rare cause of DVT. This anomaly should be considered as a cause of bilateral and proximal DVT, in particular, in young patients without major risk factors.
Keywords: Anomaly; Azygos continuation; Computed tomography; Venous thromboembolism.