A rare case of congenital complex pulmonary AV fistula.

A 15-year-old boy presented with central cyanosis with clubbing and dyspnoea on exertion. Cardiovascular examination did not reveal any abnormality. ECG was normal. Chest X-ray showed a normal sized heart with rounded opacities of variable size in the left upper lung field. Two-dimensional echocardiographic examination was normal. CT angiography showed a large complex lesion composed of serpiginous tubular structures involving the left upper and lingular lobe, suggestive of racemose tangle of blood vessels. A diagnosis of large complex arteriovenous (AV) fistula involving the left upper and lingular lobe was performed. This case reports a rare case of complex pulmonary AV fistula.