Radiology_Oct04 Introduction Pulmonary artery aneurysms are a rare finding in general radiological practice. The possible causes are myriad and diverse in pathophysiolo- gy. Patients with post-stenotic dilata- tion of the main pulmonary artery usually present fairly late with insidi- ous cardiorespiratory symptoms. Diagnosis requires radiological imag- ing assistance as the clinical findings are nonspecific. Case report A 73-year-old woman presented to our medical outpatient department with gradually progressive dyspnoea over the past 2 years. The breathless- ness was initially present on exertion. At the time of assessment, however, she had progressed to grade III dysp- noea with associated palpitations, especially on exertion. She had no other significant preceding medical history. Clinical examination revealed early diastolic and long mid-systolic murmurs along the left heart border. She also had a 3 cm hepatomegaly and mild right heart failure. An electrocar- diogram (ECG) revealed slight right axis deviation and ventricular extrasystoles. A chest radiograph done on admission demonstrated massive expansion of the left cardiac border with markedly increased cardio- thoracic ratio. There were no radio- logical features of overt cardiac failure. The aortic outline was clearly delin- eated with some age-related tortuosi- ty. Considerations at this point included giant left atrium, pulmonary artery aneurysm, giant right atrium, massive pericardial cyst or effusion (Fig. 1). We then proceeded to perform a computed tomography scan, which revealed a massively dilated main pul- monary artery as well as dilated right and left pulmonary arteries. Slight right atrial and right ventricular dilatation was also noted. The rest of the mediastinal structures were within normal limits. A diagnosis of aneurysm of the main pulmonary artery was made (Fig. 2). An echocardiogram confirmed pulmonary valvular stenosis with post-stenotic dilatation and pul- monary artery aneurysm formation. The pulmonary valve pressure gradi- ent was > 28 mmHg. The patient set- tled on low-dose diuretic therapy, and following cardiothoracic surgical con- sultation it was decided that no surgi- cal intervention was warranted. She was followed up at the clinic. Discussion Aneurysms of the pulmonary artery (PAA) are rare in adults. Predisposing conditions include con- genital and acquired heart disease, e.g. left-to-right shunting or pulmonary valve stenosis with post-stenotic dilatation. Other causes include infec- tion (tuberculosis, syphilis, osteo- myelitis, pneumonia), systemic vas- culitides (Hughes-Stovin’s disease, Behcet’s disease), collagen vascular diseases, connective tissue disorders, (Marfan’s syndrome, Ehler’s-Danlos 30 SA JOURNAL OF RADIOLOGY • October 2004 CASE REPORT Pulmonary artery aneurysm S K Misser MB ChB J M Maharajh MB ChB, MMed, FFRad (D) Department of Radiology University of Kwa-Zulu-Natal Nelson R Mandela School of Health Sciences and King Edward VIII Hospital Durban Fig. 1. Postero-anterior chest radiograph per- formed on admission. Fig. 2. Axial CT scan of the chest at the level of the main pulmonary artery. CASE REPORT 31 SA JOURNAL OF RADIOLOGY • October 2004 syndrome), trauma (direct or blunt chest injury), mucoid vasculopathic changes and idiopathic PAA.1 Irrespective of the underlying cause, most PAA are associated with pulmonary arterial hypertension. Clinically patients usually present with symptoms of mild congestive heart failure of insidious onset, haemoptysis and bronchial compres- sion, or the aneurysm is discovered incidentally on chest radiography for unexplained dyspnoea.2 Post-stenotic dilatation of the pul- monary artery is a common feature of pulmonary stenosis, but does not usu- ally reach aneurysmal proportions. In most cases of post-stenotic dilatation the main or left pulmonary artery is involved. One plausible explanation for this is the sharp angle at which the right pulmonary artery emerges, causing the near-vertical, high-veloci- ty jet to bypass its origin.3 In the patient reported here the degree of dilatation was marked and both right and left pulmonary arteries were involved. A possible associated degen- erative process (especially since she was in her 8th decade) is thought to be responsible for this appearance. Clinical response to routine antifailure/diuretic therapy is usually good, but the response cannot be predicted. Long-term outcome of untreated PAA is not well document- ed. One-third of patients with PAA, from all causes, will die from aneurysm rupture. Aneurysms associ- ated with post-stenotic dilatation per- sist after treatment but are of no clini- cal significance. Recent reports have described the use of balloon valvulo- plasty in correcting the valvular steno- sis with resultant reduction in pul- monary arterial pressures and aneurysm stability.4 Our patient responded very well to medical therapy and her symptoms have almost completely settled. We shall continue to re-assess her clinical status as well as the trans-pulmonary valve pressure gradient as an index of stability. Acknowledgements Special thanks to Professor P Corr for editing the manuscript, Mr Steve Odayan (Chief Radiographer) for assistance with imaging and Ms Marianne Singh for technical support. References 1. Deterling RA, Clagett OT. Aneurysms of the pulmonary artery. Am Heart J 1947; 34: 471. 2. Lopez-Candales A, Kleiger RE, Aleman-Gomez J, Kouchoukos NT, Botney MD. Pulmonary artery aneurysm: Review and case report. Clin Cardiol 1995; 18: 738-740. 3. Tami LF, McElderry MW. Pulmonary artery aneurysm due to severe congenital pulmonic stenosis. Case report and literature review. Angiology 1994; 45: 383-390. 4. Butto F, Lucas RV, Edwards JE. Pulmonary artery aneurysm: a pathological study of five cases. Chest 1987; 91: 237-240.