Acquired supravalvular pulmonary stenosis due to extrinsic compression by a mediastinal dermoid cyst.

Acquired pulmonary stenosis is rare. When it occurs, it usually results from compression of the pulmonary artery or the heart by a mediastinal tumour. As these masses rarely cause compression that results in murmurs, it is hard to make a diagnosis. We describe a 23-year-old female patient who presented with dull, aching chest pain lasting for 6 months. Echocardiography showed a large anterior mediastinal cystic mass compressing the main pulmonary artery. She was operated through a left anterolateral thoracotomy and had an uneventful recovery.