Abstract
A 65-year-old woman with immunoglobulin G4-related disease (IgG4-RD), which was managed with a corticosteroid, underwent percutaneous coronary stent implantation in the left anterior descending artery as a result of angina pectoris. After 9 months, coronary angiography revealed stent migration and occlusion caused by progression of a coronary aneurysm potentially associated with IgG4-RD. (Level of Difficulty: Advanced.).