A Case of Immunoglobulin G4-Related Thoracic Aortic Aneurysm Initially Diagnosed as Aortic Intramural Hematoma

Minoru Matsuhama＊	Takuma Kobayashi＊＊	Takashi Kunihara＊
Tomoyuki Goto＊＊

（Department of Cardiovascular Surgery, The Cardiovascular Institute＊, Tokyo, Japan, and Department of Cardiovascular Surgery, Kyoto Okamoto Memorial Hospital＊＊, Kyoto, Japan）

Immunoglobulin G4（IgG4)-related disease is a chronic disease characterized by fibrotic mass and/or thickened lesions with elevated serum IgG4 concentrations, and infiltrations of IgG4 positive plasma cells. Since it has recently been reported to occur in the cardiovascular system, therapeutic strategy needs to be established. We report a case of IgG4-related thoracic aortic aneurysm（IgG4-R TAA）which was diagnosed postoperatively though suspected as aortic intramural hematoma preoperatively. A 70-year-old man who has medical histories of retroperitoneal fibrosis twice visited our hospital with chief complaints of cough and a CT scan was performed. Though there had been no episodes related to the onset of aortic dissection such as chest pain, an ascending aortic intramural hematoma of 52mm in diameter was suspected and we planned to perform hemi-arch replacement. Intraoperative findings suggested that it was a true aneurysm and there was no sign of dissection. Histopathologically, the adventitia was obviously thickened with infiltrations of IgG4 positive plasma cells without infiltrations and dissection findings in the tunica media. In addition, serum IgG4 exceeded the normal value, thus it was diagnosed as IgG4-R TAA on the basis of the comprehensive diagnostic criteria. Great caution should be taken in IgG4-R TAA because it may show intramural hematoma on imaging and may develop aortic dissection and rupture as well.

 

Jpn. J. Cardiovasc. Surg. 47:88-92（2018）

Keywords：IgG4-related disease;aortic dissection;intramural hematoma;diagnostic criteria