This individual likely has Marfan syndrome. The large-artery complication associated with this condition is aortic dissection resulting from cystic medial degeneration.
The development of aortic dissection and aneurysm often involves cystic medial degeneration, characterized by myxomatous changes in the media of large arteries. The elastic tissue of the media becomes fragmented, with separation of the components and filling in of amorphous extracellular matrix. Individuals with Marfan syndrome are at risk for this due to the autosomal dominant defect in fibrillin-1, a component of the extracellular matrix.
McConaghy and Oza describe the diagnosis of acute thoracic aortic dissection in outpatients presenting with acute chest pain. Aortic dissection often presents with acute chest or back pain. While physical exam is only modestly helpful at ruling in or out the condition, the sign to look for is a blood pressure differential in the upper extremities.
Ho et al. review Marfan syndrome and its associated complications. The authors report that while Marfan syndrome is an autosomal dominant condition with complete penetrance, there is variable expression and age dependency. Furthermore, up to a quarter of affected individuals have no family history of the disease, resulting from new mutations.
Illustration A is an example of cystic medial degeneration of the aorta resulting in dissection. It shows focal degeneration of elastic tissue, and muscles in the tunic media. The black arrow identifies the tunica intermedia and the red arrow the tunica adventitia.
Answer 1: Focal granulomatous inflammation with mural lymphocytes, macrophages, giant cells is typical of giant cell/temporal arteritis and Takayasu arteritis.
Answer 2: Churg-Strauss syndrome is characterized by eosinophilic vasculitis.
Answer 3: Polyarteritis nodosum is characterized by predominant neutrophilic infiltration with fibrinoid necrosis.
Answer 4: Fibrinoid necrosis of blood vessel walls, endothelial swelling, and neutrophilic infiltrate in skin lesions are findings of Henoch-Schonlein purpura.
McConaghy JR, Oza RS. Outpatient diagnosis of acute chest pain in adults. Am Fam Physician. 2013 Feb 1;87(3):177-82. Review. PubMed PMID: 23418761.
PMID:23418761 (Link to Abstract)
Ho NC, Tran JR, Bektas A. Marfan's syndrome. Lancet. 2005 Dec 3;366(9501):1978-81. Epub 2005 Aug 2. Review. PubMed PMID: 16325702.
PMID:16325702 (Link to Abstract)
USMLE World Step 1 QBank Question #462. Copyright © USMLEWorld, LLC 2012