Pulmonary arteriovenous malformation.

Abstract

A 46-year-old man with facial telangiectasias and recurrent epistaxis had worsening dyspnea on exertion. Laboratory examination revealed chronic hypoxemia and secondary polycythemia. A chest radiograph (Fig. 1A) showed a right apical lung opacity. CT (Fig. 1B) showed a large enhancing cluster of tubular structures in the apical segment of the right upper lobe and several smaller similar lesions in the left lung. Angiography (Fig. 1C) confirmed the impression that these were pulmonary arteriovenous malformations (AVMs). A partially thrombosed AVM (Fig. ID) occupying most of the right upper lobe was removed at lobectomy. The final clinicopathologic diagnosis was pulmonary AVM in hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu disease. Before the CT scan. the patient had not been known to have HHT. HHT is a systemic fibrovascular dysplasia with autosomal dominant transmission in which telangiectasias. AVMs, and aneurysms are widely distributed throughout the vascular system [ 1 , 2]. More than one third of patients with solitary pulmonary AVMs and more than half of patients with multiple pulmonary AVMs have HHT [3], and these patients have a worse clinical course than patients without HHT. Chest radiographs nearly always show abnormalities; a single peripheral circumscribed noncalcified mass connected by vessels to the hilum is the most common finding. CT can define additional lesions and assist in showing the connection to the hilum, but angiography will show the number, extent, and location of the lesions and will delineate the arterial supply and venous drainage for surgical planning. Patients with HHT may present in a vanety of ways: recurrent bleeding from mucosal telangiectasias and AVMs: hypoxemia, polycythemia, cerebral embolism, and brain abscess from pulmonary shunts; highoutput congestive heart failure and portosystemic encephalopathy from hepatic AVMs; and seizures, visual loss, and cerebellar dysfunction from central nervous system angiodysplasia 121. Surgical resection of pulmonary AVMs has been advocated to decrease the risk of stroke, infection, and spontaneous rupture. even in asymptomatic patients, but resection may be problematic when multiple lesions are present. Transcatheter embolization with coils [4] and detachable balloons 15] is an alternative to surgery. especially when multiple lesions are present and the preservation of functional lung tissue is critical.