Abstract: @@ Pulmonary vein varix, congenital or acquired dilation of the pulmonary vein, is a rare vascular abnormality.This disease often presents as a pulmonary mass on chest roentgenography, and pulmonary angiography, computed tomography (CT), or magnetic resonance imaging (MRI)is considered necessary for diagnosis.1 The diagnosis of the disease by thoracic exploration is rare because the present case was diagnosed as a pulmonary arteriovenous fistula before operation.