Immunoglobulin G4-related solitary aneurysm of the deep femoral artery

We have reported the case of an 83-year-old man with a rare immunoglobulin G4 (IgG4)-related solitary deep femoral artery aneurysm. The patient successfully underwent aneurysmectomy and vascular reconstruction with an expanded polytetrafluoroethylene graft. A definitive diagnosis was determined from the comprehensive diagnostic criteria, including histopathologic features of chronic inflammation indicated by massive infiltration of IgG4-positive plasma cells. IgG4-related aneurysmal diseases should be included in the differential diagnosis of deep femoral artery aneurysms, which have traditionally been considered to develop owing to previous trauma or surgery, intervention, infection, and autoimmune or collagen disease.