Abstract
A 92-year-old woman visited the hospital with edema of both lower extremities. Computed tomography revealed her inferior vena cava (IVC) was compressed by a massive hepatic cyst. A massive IVC thrombosis and pulmonary thromboembolism (PTE) were also observed. Medical treatment rather than radiologic intervention was preferred because of the patient's advanced age and poor performance status. IVC thrombosis and PTE disappeared after 6 months of anticoagulation therapy. To the best of our knowledge, this is the first study in the English literature to report IVC thrombosis caused by congenital hepatic cysts that was treated without vascular intervention.