A 57-year-old man with an idiopathic aneurysm of the left pulmonary artery
is presented. The aneurysm was stable over many decades. No such long-term
follow-up of an idiopathic pulmonary aneurysm has been described previously
. After 39 years there is no evidence of heart failure or pulmonary hyperte
nsion. Because corrective surgery has a variable outcome, and prognosis is
suggested to be good in the idiopathic form of pulmonary aneurysm, no surgi
cal correction was proposed.