Acquired pulmonary stenosis: ultrasonographic diagnosis.

A 15-year-old boy presented with chest pain and a new heart murmur. The clinical diagnosis of pulmonary stenosis was confirmed by two-dimensional and Doppler echocardiographic examinations. A large, encapsulated, partly solid and partly cystic tumor in the anterior mediastinum, visualized by ultrasonography, was compressing the main pulmonary artery and producing the right ventricular outflow tract obstruction. The tumor was removed surgically and was found to be a benign teratoma. Postoperative ultrasound examination of the right ventricular outflow tract showed no evidence of obstruction. We conclude that: (1) there are subtle clinical diagnostic differences between intrinsic and extrinsic pulmonary stenosis; (2) ultrasound examination can make cardiac catheterization unnecessary; and (3) relief of the extrinsic cause of pulmonary stenosis should be curative.