Introduction: The natural history of pulmonary artery aneurysm (PAA) is poorly understood due to the limited number of cases diagnosed ante-mortem. Aneurysms of the proximal pulmonary artery are found in approximately 1 in 14000 postmortem examinations. The pulmonary artery trunk is considered aneurysmal when the diameter exceeds 4 cm.
Case Report: A 62-year-old woman with rheumatoid arthritis, moderate COPD (requiring supplemental oxygen), untreated obstructive sleep apnea, moderate pulmonary hypertension (mean pressure of 40 mmHg), 90 pack years smoking history and HFpEF presented to the hospital with acute on chronic hypoxemic respiratory failure. The patient was noted to have a pulmonary artery aneurysm measuring 6 cm in diameter on a computed tomography scan obtained to rule out pulmonary embolism. We believe the mechanism of PAA in our patient to be secondary to the structural changes in elastin and collagen due to increased pulmonary artery pressure leading pulmonary artery dilation and subsequent aneurysm. Due to poor pulmonary reserve, patient is not considered a good candidate for surgical intervention and conservative management was opted in her case.
Conclusion: Pulmonary artery aneurysm continues to remain a poorly understood disease entity. Treatment options are often limited by late/acute presentations and multiple co-morbidities. However, advances in imaging and higher degree clinical suspicion allow for earlier identification of PAAs and allow for appropriate intervention. We hope that our case report will allow medical providers to be on the look-out for PAAs in patients with above mentioned risk factors.

Keywords: Aneurysms, Pulmonary artery, Pulmonary hypertension