Findings: A frontal view of the chest demonstrates multiple pulmonary nodular densities with prominent overlying vascular structures adjacent to the nodules.
CT images through the chest demonstrate multiple nodular densities throughout both lungs with prominent feeding arteries and veins. There is associated thrombosis within the right middle lobe lesion.
Diagnosis: Multiple pulmonary arteriovenous malformations.
Discussion: Pulmonary arteriovenous malformations consist of a direct communication between the pulmonary artery and pulmonary vein. Approximately 60 to 90% of patients with pulmonary AVMs are affected with hereditary hemorrhagic telangiectasia or Osler-Weber-Rendu disease. Symptoms include dyspnea, fatigue, cyanosis and clubbing. Many AVMs present during adult life, however, symptoms can usually be traced back to childhood.
There are several different types of pulmonary arterial vascular malformations. A simple AVM consists of a single pulmonary artery to pulmonary vein communication. On the other hand a complex malformation consists of multiple feeding arteries and draining veins. In both of these lesions the communication is aneurysmal. However, the simple lesions are nonseptated while the complex lesions are always septated. In addition, the simple AVM is the more common lesion occurring in approximately 79% of patients analyzed while the complex lesion occurred in approximately 21% of patients analyzed in a study by White, et al.
Higgins and Wexler further categorized pulmonary AVMs into solitary, multiple of varying size, multiple of uniform size and diffuse.
The goal of treatment includes prevention of possible complications as well as relief of symptoms including dyspnea and fatigue. In the past, surgical excision of the lesions was the treatment of choice. However, embolotherapy is currently the treatment of choice.
Possible complications from pulmonary AVMs include cerebral abscess, cerebral embolism, hemothorax and hemoptysis.
References:
Baum S. Abrams' Angiography, 4th Edition. Little Brown and Company,
Boston; 1997:794-795.
Higgins C, Wexler L. Clinical and Angiographic Features of Pulmonary
Arteriovenous Fistulas in Children. Radiology. 1976;119:171-175.
Lanzieri C, et al. Neurology Case of the Day. American Journal of
Radiology. 1997;169:299-302.
White RI, Mitchell SE, Barth KH, et al. Angioarchitecture of Pulmonary
Malformations: An Important Consideration Before Embolotherapy. American
Journal of Radiology. 1983;140:681-686.
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