Contrast transesophageal echocardiography in the diagnosis and localization of diffuse pulmonary telangiectasias.

Pulmonary arteriovenous fistulas are rare, usually related to the Rendu-Osler-Weber syndrome, and are detected by chest CT scan or pulmonary angiography. In a 14-year-old boy without Rendu-Osler-Weber syndrome, but with clinical evidence of a right-to-left shunt, ancillary diagnostic studies were negative for pulmonary arteriovenous fistulas, and the final diagnosis was made by contrast transesophageal echocardiography. Saline echo-contrast medium injected peripherally was seen emerging from each pulmonary vein and filling the left chambers. These findings, in light of other negative test results, established the diagnosis of diffuse telangiectasias at the capillary level in both lungs. After 6 years of medical therapy, the patient remains cyanotic but functions well.