Pulmonary Arteriovenous Fistula: Clinical and Histologic Spectrum of Four Cases

Abstract

Pulmonary arteriovenous fistula (PAVF) is abnormally dilated vessels that provide a right-to-left shunt between pulmonary artery and pulmonary vein and is clinically divided into simple and complex type. Here, we report four cases of surgically resected sporadic PAVFs presenting various clinical and histologic spectrums. Cases 1 (a 57-old-female) and 2 (a 54-old-female) presented as incidentally identified single aneurysmal fistulas and the lesions were surgically removed without complication. On the other hand, case 3 (an 11-old-male) showed diffuse dilated vascular sacs involving both lungs and caused severe hemodynamic and pulmonary dysfunction. Embolization and surgical resection of the main lesion failed to relieve the symptoms. Case 4 (a 36-old-male) had a localized multiloculated cyst clinically mimicking congenital cystic adenomatoid malformation. Microscopically, the lesion consisted of dilated thick vessels, consistent with the diagnosis of fistulous arteriovenous malformation/hemangioma.

Keywords: Arteriovenous fistula; Arteriovenous malformations; Lung.

Fig. 1.

Pulmonary arteriovenous fistula (PAVF). (A–F) Radiologic, gross, and microscopic features of two simple PAVF cases. (A, D) Both incidentally identified lesions are shown as dilated aneurysmal sacs in chest computer tomography (CT). (E) The cut section of case 2 shows a thin-walled cyst with smooth whitish inner surface. Microscopically, they consist of irregularly shaped aneurysmal dilation of thick vein (B, F) and hypertrophic arteriopathy of pulmonary arteriols around the main aneurysmal vein is accompanied in case 1 (C). (G–I) Radiologic, gross, and microscopic features of diffuse PAVF case. (G) Chest CT reveals severe vascular engorgement on both lungs. (H) On the cut section, many engorged vessels with blood clots are shown. (I) Microscopically, many dilated thin veins filled with blood are identified. (J–L) Radiologic, gross, and microscopic features of fistulous arteriovenous malformation/hemangioma. (J) Chest CT shows a multi-cystic lesion in the lateral side of right lung showing vascular supply through the intercostal arteries or pulmonary arteries. (K) The cut section of right lower lobectomy specimen shows a multi-lobulated cystic lesion filled with blood. (L) Microscopically, the cystic lining consists of dilated vascular structure.