Abstract
A patient with a circulating lupus anticoagulant in the absence of systemic lupus erythematosus developed recurrent deep venous thromboses and pulmonary emboli. Pulmonary emboli recurred despite prolonged oral anticoagulant therapy and resulted in fatal pulmonary arterial hypertension. Extended anticoagulant therapy alone may not prevent recurrent thromboembolism in patients with a lupus anticoagulant. Pulmonary thromboembolism may be an important factor in the pathogenesis of pulmonary hypertension in patients with a lupus anticoagulant.