Giant popliteal venous aneurysm presenting with pulmonary embolism: multimodal imaging findings and clinical course.

Popliteal venous aneurysm is a rare vascular abnormality that is an important cause of pulmonary embolism. This case report focuses on a 71-year-old woman who presented with exertional dyspnea and transient loss of consciousness. Transthoracic echocardiography revealed marked right atrial and ventricular enlargement with interventricular septal flattening, suggesting right heart overload. Contrast-enhanced computed tomography revealed bilateral pulmonary emboli and a markedly dilated left popliteal vein with an intraluminal thrombus consistent with a giant popliteal venous aneurysm. Duplex ultrasonography of the lower extremities further demonstrated thrombus formation, with markedly reduced and stagnant blood flow. Anticoagulation therapy resolved the pulmonary emboli and improved the right ventricular overload; however, the thrombus persisted within the aneurysm. Subsequently, surgical repair was performed to prevent recurrence. This case highlights the importance of multimodal imaging for diagnosis, risk assessment, and management of venous aneurysm-associated pulmonary embolism.