Solitary pulmonary nodule due to pulmonary arteriovenous malformation

A female patient, 48 years old, non smoker, with unremarkable personal history admitted to our hospital due to dysuria. The patient presented no respiratory symptoms. There where no mucosal or skin telangiectasias or other abnormal physical findings. SpO(2) was 98% in room air. The laboratory tests were compatible to urinary tract infection. The Chest x-ray (Figure 1) showed a round, non-calcified nodule on the right middle lobe, connected with the right hilum by a linear shadow. It represents a "typical" radiological picture of a solitary pulmonary arteriovenous malformation (PAVM) 1. Chest CT scan (Figure 2) showed a nodule of 1.8 cm diameter with contrast enhancement, connecting to blood vessels, a picture compatible to a solitary pulmonary arteriovenous malformation. The patient was referred to an Interventional Radiology center for further management (embolization assessment). PAVM is a rare abnormality of pulmonary vasculature and in most cases it correlates to Hereditary Hemorrhagic Telangiectasia syndrome. It is characterized by direct communication of a pulmonary artery branche to a pulmonary vein, without the presence of a capillary network.