IgG4‐related systemic disease accounts for a significant proportion of thoracic lymphoplasmacytic aortitis cases

IgG4-related systemic disease, a disorder recognized only recently, can cause lymphoplasmacytic inflammation in the thoracic aorta. The percentage of cases caused by IgG4-related systemic disease is not known. We aimed to determine the percentage of noninfectious thoracic aortitis cases that are associated with IgG4-related systemic disease and to establish pathologic criteria for identifying involvement of the thoracic aorta by this disorder.We...