Regarding the involvement of large vessels, we can find ourselves with aortitis-periaortitis consisting of diffuse arterial wall thickening with non stenotic mass surrounding the arteries (with the presence or not of inflammatory aneurysms); multiple-vascular region involvement is common, the iliac arteries and infrarenal abdominal aorta are the most common sites, followed by thoracic aorta and its main branches (cases 1, 2).

Small and medium-sized arteries can also be affected but it is less common. We can also find involvement of the coronary arteries such as coronary arteritis and aneurysms, which manifest as periarterial fibrosclerotic thickening that occurs as a pseudotumor formation surrounding the coronary arteries also known as the “pigs-in-a-blanket” sign, a specific finding of IgG4-related coronary involvement (case 3).

It is sometimes found by chance because of the complication of myocardial ischemia. It can be easily found by CT imaging, especially by coronary CT scan. 18FDG-PET imaging shows FDG uptake at the lesion, which indicates the coronary artery has an active inflammation and significantly responds to steroid therapy. This pseudotumor consists of lymphoplasmacyte infiltration and fibrous proliferation, findings that are similar to the histological findings of idiopathic retroperitoneal fibrosis. Therefore, IgG4-related pseudotumors and idiopathic retroperitoneal fibrosis might share a common pathogenesis.