Never forget the aorta: a case report of IgG4-related disease causing aortitis

Background: Chest pain is a common reason for admission to the Emergency Department and aortic disease is a relatively frequent cause amongst the total number of admissions due to chest pain. IgG4-related disease (IgG4-RD) is a multi-organ immune-mediated condition that mimics several malignant, infectious, and inflammatory disorders.

Case summary: We report a rare case of IgG4-related aortitis complicated with severe aortic regurgitation and multivessel coronary artery disease in a 64-year-old man with a history of atypical chest pain. The diagnosis was made performing transthoracic echocardiography, transoesophageal echocardiography, and left heart catheterization; the aortitis was an incidental finding discovered by computed tomography angiography. Unusually, the positron emission tomography-computed tomography (PET-CT) scans did not reveal metabolic activity in the aortic wall. This last finding prompted us to exclude more aggressives arteritis (such as Horton's disease or Takayasu arteritis); syphilis infection and other infective or autoimmune diseases were excluded with laboratory tests. The patient underwent cardiac surgery with replacement of both the aortic valve and the ascending aorta, also performing a coronary aortic bypass graft (CABG). Despite the PET-CT scans were negative in the aortic wall, the histological specimens showed diffuse lymphoid infiltration, fibro-atheromatosis lesions, and medium-interstitial hyperplasia compatible with aortic atherosclerosis and IgG4-RD. The post-surgery course was free of complications and the patient was discharged in good clinical condition. He was referred to the Rheumatologic Department and a corticosteroid therapy has been started.

Discussion: The growing recognition of IgG4-related systemic disease as a clinical entity underscores the importance of considering this diagnosis in patients with any type of idiopathic aortitis and aortic valve disease. Noteworthy, the PET-CT scans could be negative in this disease, so histological exams are mandatory to make the diagnosis; in our case an unusual post-surgery histopathological finding prompted us to diagnose a rare, unrecognized disease and allowed us to treat the patient properly.