Table II.

Summary of the main features of the most frequently encountered infectious aortitis.

	Preferential site	Pathogenetic mechanism	Histology
Bacterial aortitis	Abdominal aorta	Seeding of aortic wall at previously damaged sites	Diffuse colliquative necrosis
Q fever aortitis	Abdominal aorta	Seeding of aortic wall at previously damaged sites	Diffuse colliquative necrosis and non-necrotizing granulomatous inflammation
Syphilitic aortitis	Thoracic aorta	Hematogenous spread and colonization from vasa vasorum	Lymphoplasmacytic infiltrate around vasa vasorum with occasional giant cells and microgummas
Mycobacterial aortitis	Descending aorta	Direct spread from infected tissue (e.g., lymph nodes)	Granulomatous inflammation with caseous necrosis
Fungal aortitis	Abdominal aorta	Seeding of aortic wall at previously damaged sites	Diffuse colliquative necrosis and necrotizing granulomatous inflammation