RESUMEN
We report the case of a patient, a 19-year-old young man, with a rare malformation of the pulmonary blood vessels--a complex arteriovenous (A-V) fistula. The disease was characterized by typical signs of the right-to-left shunt: cyanosis, clubbed fingers and exertional dyspnea. Hypoxemia and polyglobulia were present in the blood examination findings and functional tests showed significantly reduced diffusion lung capacity and progressive dyspnea, while ergometry revealed cyanosis. The physical examination, ECG and ultrasound of the heart were normal as well as aortography. The final diagnosis was made by pulmonary angiography which showed a complex A-V malformation of several feeding arteries and profuse initial multiple venous drainage. Following a successful surgical procedure the diagnosis was also confirmed histopathologically-diffuse teleangiectatic A-V fistula of the lower lobe of the left lung. Following surgery cyanosis, dyspnea, hypoxemia and polyglobulia disappeared and the young man has been well for the following two years.