Incidental Ascending Aortitis: The Histologic and Clinical Spectrum
Lauren Xu, Lindsay Goicochea, Fabio Tavora, Allen Burke. University of Maryland Medical Center, Baltimore, MD; Messejana Heart and Lung Hospital, Fortaleza, CE, Brazil
Background: The incidence of aortitis in series of aortic aneurysm repair is between 5 and 8%. In most cases, the diagnosis is made initially by histopathologic evaluation of the specimen. There are few single-institution clinicopathologic series of aortitis.
Design: We prospectively studied histologic features of aortitis in series of repaired aortic aneurysms over a 6-year period with clinical correlation and follow-up.
Results: Of 254 aortic resections, there were 17 cases of incidental aortitis (6.7%); 9 women (74 ± 13 years) and 8 men (62 ± 15 years). 4 patients had prior autoimmune disease (rheumatoid arthritis, giant cell arteritis, ankylosing spondylitis, and IgA nephropathy); 1 was diagnosed subsequently with Takayasu disease. Additional 3 patients had positive rheumatoid factor and ANA, history of Lyme disease, and fibromyalgia. Grossly, all cases of aortitis showed a distinct wrinkled intima. The surgeon noted abnormal thickened aortic wall intraoperatively in 8 cases. Histologically, there were two types of aortitis: necrotizing aortitis and periaortitis. Necrotizing aortitis demonstrated three phases: acute, healing, and healed. In the acute phase (n=3), there were linear zones of necrosis > 3 mm with peripheral predominately adventitial macrophage giant cells; 2 cases also showed pockets of neutrophils. In the healing phase (n=5), there was both zonal medial necrosis < 3 mm with surrounding granulomatous reaction, and areas of healing with smooth muscle cell proliferation, often with proteoglycans mimicking cystic medial degeneration. In the healed phase (n=7), only the latter changes were noted. All cases showed brisk adventitial chronic inflammation and scattered inflammatory infiltrates around medial vessels. The two cases of periaortitis had numerous (>25 per hpf) IgG4 plasma cells and adventitial fibrosis. Intimal and adventitial thickening was mild in necrotizing aortitis (mean 0.6 and 0.9 mm, respectively) and greater in IgG4 disease (mean 4.2 and 1.3 mm, respectively). 2 patients with necrotizing aortitis progressed with new descending aortic aneurysms. One of these patients was treated with immunosuppressive treatment and one with anti-inflammatory drugs; they were the only patients given systemic treatment.
Conclusions: Aortitis is the cause of about 7% of surgically repaired ascending aortic aneurysms. Most cases show necrotizing medial inflammation that heals with a characteristic histologic appearance. IgG4 disease is a less common cause of aortitis that involves primarily the adventitia.
Wednesday, March 6, 2013 9:30 AM
Poster Session V # 53, Wednesday Morning