[Pulmonary arterio-venous malformation protruding from the pleural surface in a case of Rendu-Osler-Weber disease].

A 57-year-old woman complaining of dyspnea on exertion and left back pain was admitted to our hospital. Chest X-ray films revealed a nodular lesion in the lower left lung field. Enhanced chest computed tomography (CT) scans demonstrated a nodular lesion communicating with a dilated pulmonary artery and vein in the subpleural region of the left S9. The presence of cutaneous telangiectases, repeated epistaxis and a family history of arteriovenous malformation (AVM) indicated a diagnosis of pulmonary AVM during a course of Rendu-Osler-Weber disease. Lobectomy of the left lower lung was performed. The AVM appeared to be located in the subpleural region of the left S9 on chest CT images. However, it was actually located in the left S9 and was protruding from the pleural surface. The wall of the AVM appeared very flimsy and was likely to rupture easily.