Diagnosis: Giant Cell Arteritis (GCA)
• GCA most often involves the arteries of the head and neck and major branches of the aorta, although many other organs can also be affected in select cases, including the heart, lungs, liver, small bowel, and kidneys.
• The vasculitis begins in the medial or adventitial layer of the blood vessel and expands to involve the intima.
• Only focal fibrinoid necrosis is seen in cases of GCA. If necrosis is severe, the possibility of another type of vasculitis instead of GCA should be entertained.
• The vessel wall inflammation, often centered on the internal elastic lamina, leads to fragmentation of the elastica. These fragments sometimes can be seen within the cytoplasm of multinucleated giant cells or macrophages.
• Thrombosis is not a common finding as it is in necrotizing vasculitis.
