Immunoglobulin G4-related hepatic artery aneurysm.

A 49-year-old man who was a current smoker with a history of hypertension, dyslipidemia, and coronary artery disease after coronary stent placement presented because of abdominal and back pain. Contrast-enhanced computed tomography showed a 30-mm, large hepatic artery aneurysm. Resection of the aneurysm and autogenous vein bypass grafting was performed, which resulted in a successful outcome without any complications. Pathologic examination of the aneurysm confirmed that it was related to immunoglobulin G4 (IgG4). The patient's serum IgG4 level was within the normal range, and no other signs of IgG4-related organ lesions were observed.