A rare pair: two cases of clinically isolated pulmonary artery aneurysm.

Pulmonary artery aneurysms (PAAs) are a rare pathology with potentially devastating consequences. In this case series, we describe two cases of clinically isolated pulmonary arteritis and concisely review the literature surrounding this new clinical entity. Two Caucasian women, aged 65 and 73, were referred to our cardiovascular surgery center with incidental PAAs, both growing to over 65 mm in main pulmonary artery diameter. Both participants underwent serial thoracic CT-angiograms to monitor the pulmonary artery aneurysms. Both pulmonary artery aneurysms showed an interval increase in diameter, so they were repaired surgically. The main pulmonary artery was excised in both cases and replaced with a synthetic graft. No pre- or postoperative corticosteroids were administered. Neither of our patients had systemic symptoms of giant cell arteritis or elevated inflammatory markers. In both cases, only the main pulmonary artery was replaced to minimize surgical complexity and risk; however, the left pulmonary artery of one patient began to further dilate 5 years postoperatively. Currently, no reintervention is planned. These cases represent mounting evidence for the existence of clinically isolated pulmonary arteritis leading to a pulmonary artery aneurysm. This entity is analogous to clinically isolated aortitis and may represent a subclinical smoldering vasculitis. These rare aneurysms can progress over time and require surgical intervention. In the absence of guidelines for pulmonary artery aneurysm intervention, the present cases will serve to guide further management of this rare disease.