CH7 - Vascular Pathology Flashcards
What is vasculitis?
Inflammation of the blood vessel wall
What is the arterial wall comprised of?
three layers: endothelial intima, smooth muscle media, and connective tissue adventitia
What is the etiology for vasculitis?
usually unknown; most cases are not infectious.
What do the clinical features for vasculitis include?
1) Nonspecific symptoms of inflammation (e.g., fever, fatigue, weight loss, and myalgias) 2) Symptoms of organ ischemia—due to luminal narrowing or thrombosis of the inflamed vessels
Why are there symptoms of organ ischemia in vasculitis?
Its due to luminal narrowing or thrombosis of the inflamed vessels
How is vasculitis divided?
into large-, medium-, and small-vessel vasculitides
What does large-vessel vasculitis involve?
the aorta and its major branches.
What does medium-vessel vasculitis involve?
muscular arteries that supply organs.
What does small-vessel vasculitis involve?
arterioles, capillaries, and venules.
What are the large vessel vasculitis?
Temporal (Giant Cell) Arteritis and Takayasu Arteritis
What is temporal (Giant Cell) Arteritis?
Granulomatous vasculitis that classically involves branches of the carotid artery
What is the most common form of vasculitis in older adults (> 50 years)?
temporal (Giant Cell) Arteritis and usually affects females
How does temporal (Giant Cell) Arteritis present?
as headache (temporal artery involvement), visual disturbances (ophthalmic artery involvement), and jaw claudication. Flu-like symptoms with joint and muscle pain (polymyalgia rheumatica) are often present. ESR is elevated.
What does biopsy of temporal (Giant Cell) Arteritis reveal?
inflamed vessel wall with giant cells and intima fibrosis
How do the lesions appear?
They are segmental;
What does diagnosis of temporal (Giant Cell) Arteritis require?
biopsy of a long segment of vessel, and a negative biopsy does not exclude disease.
What is the treatment for temporal (Giant Cell) Arteritis?
it is corticosteroids; high risk of blindness without treatment
What is Takayasu Arteritis?
Granulomatous vasculitis that classically involves the aortic arch at branch points
Takayasu Arteritis presents in?
adults < 50 years old (classically, young Asian females) as visual and neurologic symptoms with a weak or absent pulse in the upper extremity (‘pulseless disease’). ESR is elevated.
What is the treatment for Takayasu Arteritis?
it is corticosteroids
What are the medium vessel vasculitis?
Polyarteritis Nodosa, Kawasaki Disease, Buerger Disease
What is Polyarteritis Nodosa?
Necrotizing vasculitis involving multiple organs; lungs are spared.
How does Polyarteritis Nodosa classically present?
in young adults as hypertension (renal artery involvement), abdominal pain with melena (mesenteric artery involvement), neurologic disturbances, and skin lesions.
What is Polyarteritis Nodosa associated with?
serum HBsAg
In Polyarteritis Nodosa what types of lesions are present?
Lesions of varying stages are present.
What does the early lesion of Polyarteritis Nodosa consist of?
transmural inflammation with fibrinoid necrosis that eventually heals with fibrosis,
How does the early lesion of Polyarteritis Nodosa appear on imaging?
It produces a string-of-pearls appearance on imaging
What is the treatment for Polyarteritis Nodosa?
corticosteroids and cyclophosphamide; fatal if not treated
Who does Kawasaki Disease classically affect?
Asian children < 4 years old
How does Kawasaki disease present?
with nonspecific signs including fever, conjunctivitis, erythematous rash of palms and soles, and enlarged cervicai lymph nodes
In Kawasaki disease involvement of what is common and what does this usually lead to?
Coronary artery involvement is common and leads to risk for (1) thrombosis with myocardial infarction and (2) aneurysm with rupture.
What is the treatment for Kawasaki disease?
It is aspirin and IVIG; disease is self-limited.
What is Buerger Disease?
Necrotizing vasculitis involving digits
How does Buerger Disease?
Presents with ulceration, gangrene, and autoamputation of fingers and toes
In Buerger Disease, what is often present?
Raynaud phenomenon
Buerger Disease is highly associated with what patient behavior?
heavy smoking; treatment is smoking cessation.
What are the small vessel vasculitis?
Wegener Granulomatous, microscopic polyangiitis, Churg-Strauss Syndrome, Henoch-Schönlein Purpura
What is Wegener Granulomatosis?
Necrotizing granulomatous vasculitis involving nasopharynx, lungs, and kidneys
What is the classic presentation for Wegener Granulomatosis?
the classic presentation is a middle-aged male with sinusitis or nasopharyngeal ulceration, hemoptysis with bilateral nodular lung infiltrates, and hematuria due to rapidly progressive glomerulonephritis.
In Wegener Granulomatosis how can you gauge disease activity?
Serum c-ANCA levels correlate with disease activity,
What does Wegener Granulomatosis Biopsy reveal?
large necrotizing granulomas with adjacent necrotizing vasculitis
What is the treatment for Wegener Granulomatosis?
it is cyclophosphamide and steroids; relapses are common,
What is microscopic polyangiitis?
Necrotizing vasculitis involving multiple organs, especially lung and kidney
What is the presentation for microscopic polyangiitis?
It is similar to Wegener granulomatosis, but nasopharyngeal involvement and granulomas are absent.
How can you gauge microscopic polyangiitis disease activity?
Serum p-ANCA levels correlate with disease activity
What is the treatment for microscopic polyangiitis?
It is corticosteroids and cyclophosphamide; relapses are common.
What is Churg-Strauss Syndrome?
Necrotizing granulomatous inflammation with eosinophils involving multiple organs, especially lungs and heart
In Churg-Strauss Syndrome what else are also present in addition to the necrotizing granulomatous inflammation?
Asthma and peripheral eosinophilia are often present.
How could you gauge Churg-Strauss Syndrome?
Serum p-ANCA levels correlate with disease activity.
What is Henoch-Schönlein Purpura?
Vasculitis due to IgA immune complex deposition
What is the most common vasculitis in children?
Henoch-Schönlein Purpura
How does Henoch-Schönlein Purpura present?
with palpable purpura on buttocks and legs, CI pain and bleeding, and hematuria (IgA nephropathy);
Henoch-Schönlein Purpura usually occurs following what?
an upper respiratory tract infection
How is Henoch-Schönlein Purpura treated?
Disease is self-limited, but may recur; treated with steroids, if severe
What is hypertension?
Increased blood pressure; may involve pulmonary or systemic circulation
What is Systemic HTN is defined as?
pressure greater than 140/90 mm Hg (normal < 120/80 mm Hg);
How is HTN divided and what is this division based on?
divided into primary or secondary types based on etiology
What is primary HTN?
HTN of unknown etiology (95% of cases)
What are the risk factors for primary HTN?
They include age, race (increased risk in African Americans, decreased risk in Asians), obesity, stress, lack of physical activity, and high-salt diet.
What is secondary HTN?
HTN due to an identifiable etiology (5% of cases)
What is a common cause of secondary HTN ?
Renal artery stenosis is a common cause (renovascular hypertension).
How does renal artery stenosis lead to secondary HTN ?
1) Stenosis decreases blood flow to glomerulus. 2) juxtaglomerular apparatus (JGA) responds by secreting renin, which converts angiotensinogen to angiotensin 1. 3) Angiotensin I is converted to angiotensin 11 (ATII) by angiotensin converting enzyme (ACE).
In secondary HTN what are important causes of stenosis?
include atherosclerosis (elderly males) and fibromuscular dysplasia (young females).
What is fibromuscular dysplasia?
it is a developmental defect of the blood vessel wall, resulting in irregular thickening of large- and medium-sized arteries, especially the renal artery.
In addition to primary and secondary HTN what is another way to classify HTN?
it can also be classified as benign or malignant
What is benign HTN?
it is a mild or moderate elevation in blood pressure;
Are most cases of HTN benign or malignant?
Benign
How does benign HTN present clinically?
Its clinically silent; vessels and organs are damaged slowly over time.
What is malignant HTN?
it is severe elevation in blood pressure (> 200/120 mm Hg)
What percentage of HTN cases are malignant?
malignant HTN comprises < 5% of cases
When may malignant HTN arise?
from preexisting benign HTN or de novo
How does malignant HTN present?
with acute end-organ damage (e.g., acute renal failure, headache, and papilledema) and is a medical emergency
What is arteriosclerosis?
Literally, hard arteries; due to thickening of the blood vessel wall
What are the three pathologic patterns for arteriosclerosis ?
atherosclerosis, arteriolosclerosis, and Monckeberg medial calcific sclerosis
What is atherosclerosis?
Intimal plaque that obstructs blood flow
What does atherosclerosis consists of?
a necrotic lipid core (mostly cholesterol) with a fibromuscular cap, often undergoes dystrophic calcification
What does atherosclerosis involve?
large- and medium-sized arteries; abdominal aorta, coronary artery, popliteal artery, and internal carotid artery are commonly affected.
How are the risk factors for atherosclerosis divided?
into modifiable and nonmodiliable.
What are modifiable risk factors for atherosclerosis?
it includes hypertension, hypercholesterolemia (LDL increases risk; HDL decreases risk), smoking, and diabetes.
What are nonmodifiable risk factors for atherosclerosis?
Age, gender, genetics
How does age affect atherosclerosis?
number and severity of lesions increase with age
How does gender affect atherosclerosis?
increased risk in males and postmenopausal females; estrogen is protective
How does genetics affect atherosclerosis?
multifactorial, but family history is highly predictive of risk
What is the pathogenesis of atherosclerosis?
Damage to endothelium allows lipids to leak into the intima. 2. Lipids are oxidized and then consumed by macrophages via scavenger receptors, resulting in foam cells. Inflammation and healing leads to deposition of’extracellular matrix and proliferation o
What are fatty streaks?
flat yellow lesions of the intima consisting of lipid-laden macrophages
What are the morphologic stages in atherosclerosis?
1) Begins as fatty streaks; arise early in life (present in most teenagers) 2) Progresses to atherosclerotic plaque
What are the complications of atherosclerosis?
1) Stenosis of medium sized vessels 2) plaque rupture 3) weakening of vessel wall
What accounts for >50% of disease in Western countries?
complications of atherosclerosis
What does stenosis of medium-sized vessels result in?
impaired blood flow and ischemia
What does stenosis lead to? (what arteries are involved)
i. Peripheral vascular disease (lower extremity arteries, e.g., popliteal) ii. Angina (coronary arteries) iii. Ischemic bowel disease (mesenteric arteries)
In atherosclerosis, what does plaque rupture with thrombosis results in?
myocardial infarction (coronary arteries) and stroke (e.g., middle cerebral artery)
In atherosclerosis, what does plaque rupture with embolization result in?
atherosclerotic emboli, characterized by cholesterol crystals within the embolus
In atherosclerosis, what does weakening of vessel wall result in?
aneurysm (e.g., abdominal aorta)
What is arteriolosclerosis?
Narrowing of small arterioles
What is arteriolosclerosis divided into?
hyaline and hyperplastic types
What is hyaline arteriolosclerosis caused by?
proteins leaking into the vessel wall, producing vascular thickening;
In hyaline arteriolosclerosis what is seen on microscopy?
proteins are seen as pink hyaline on microscopy
Hyaline arteriolosclerosis is a consequence of what?
long-standing benign hypertension or diabetes
What does hyaline arteriolosclerosis result in?
reduced vessel caliber with end-organ ischemia
What does hyaline arteriolosclerosis classically produce?
glomerular scarring (arteriolonephrosclerosis) that slowly progresses to chronic renal failure
What is hyperplastic arteriolosclerosis?
it involves thickening of vessel wall by hyperplasia of smooth muscle onion-skin appearance
What is hyperplastic arteriolosclerosis a consequence of?
malignant hypertension
What does hyperplastic arteriolosclerosis result in?
reduced vessel caliber with end-organ ischemia
What may hyperplastic arteriolosclerosis lead to?
fibrinoid necrosis of the vessel wall with hemorrhage
What does the fibrinoid necrosis in hyperplastic arteriolosclerosis classically cause and how does it appear?
acute renal failure with a characteristic flea-bitten appearance
What is monckeberg medial calcific sclerosis?
calcification of the media of muscular (medium-sized) arteries; nonobstructive
How does monckeberg medial calcific sclerosis present clinically?
Not clinically significant; seen as an incidental finding on x-ray or mammography
What is aortic dissection?
Intimal tear with dissection of blood through media of the aortic wall
Where does aortic dissection occur?
in the proximal 10 cm of the aorta (high stress region) with preexisting weakness of the media
What is the most common cause of aortic dissection?
hypertension (older adults); also associated with inherited defects of connective tissue (younger individuals)
How can HTN lead to aortic dissection?
Hypertension results in hyaline arteriosclerosis of the vasa vasorum; decreased flow causes atrophy of the media.
What syndromes may lead to aortic dissection?
Marfan syndrome and Ehlers-Danlos syndrome classically leads to weakness of the connective tissue in the media (cystic medial necrosis)
What does aortic dissection present as?
sharp, tearing chest pain that radiates to the back
What are the complications for aortic dissection?
it includes pericardial tamponade, rupture with fatal hemorrhage, and obstruction of branching arteries (e.g., coronary or renal) with resultant end-organ ischemia
What is the most common cause of death in aortic dissection?
pericardial tamponade
What is a thoracic aneurysm?
A balloon-like dilation of the thoracic aorta
What is a thoracic aneurysm due to?
weakness in the aortic wall
What is a thoracic aneurysm classically seen in?
tertiary syphilis; endarteritis of the vasa vasorum
What does endarteritis of the vasa vasorum result in?
luminal narrowing, decreased flow, and atrophy of the vessel wall. Results in a tree-bark appearance of the aorta
What is the major complication for a thoracic aneurysm?
dilation of the aortic valve root, resulting in aortic valve insufficiency
What are some other (besides the major) complications of thoracic aneurysm?
compression of mediastinal structures (e.g., airway or esophagus) and thrombosis/embolism.
What is a abdominal aortic aneurysm?
Balloon-like dilation of the abdominal aorta
Where does abdominal aortic aneurysm usually arise?
below the renal arteries, but above the aortic bifurcation
What is abdominal aortic aneurysm primarily due to?
Atherosclerosis
In whom is abdominal aortic aneurysm classically seen?
in male smokers > 60 years old with hypertension
How does atherosclerosis lead to abdominal aortic aneurysm?
It increases the diffusion barrier to the media, resulting in atrophy and weakness of the vessel wall.
What does abdominal aortic aneurysm presents as?
a pulsatile abdominal mass that grows with time
What is the major complication for abdominal aortic aneurysm?
rupture, especially when > 5 cm in diameter
What does abdominal aortic aneurysm present with?
triad of hypotension, pulsatile abdominal mass, and flank pain
What are the other complications (aside from the major one)?
compression of local structures (e.g., ureter) and thrombosis/embolism.
What are the vasculartumors?
Hemangioma, angiosarcoma, Kaposi sarcoma
What is hemangioma?
It’s a benign tumor comprised of blood vessels
How does hemangioma commonly present?
at birth and often regresses during childhood
What does hemangioma most often involve?
skin and liver
What is angiosarcoma?
Malignant proliferation of endothelial cells; highly aggressive
What are the common sites for angiosarcoma?
They include skin, breast, and liver.
What is Liver angiosarcoma associated with?
exposure to polyvinyl chloride, arsenic, and Thorotrast.
What is Kaposi sarcoma?
Low-grade malignant proliferation of endothelial cells; associated with HHV-8
What does Kaposi sarcoma present as?
purple patches, plaques, and nodules on the skin, may also involve visceral organs
Kaposi sarcoma is classically seen in?
Older Eastern European males, AIDS and Transplant recipients
For Kaposi sarcoma in older Eastern European males, where is the tumor localized?
remains localized to skin
For Kaposi sarcoma in older Eastern European males, what does the treatment involve?
surgical removal
What is seen with Kaposi sarcoma in AIDS patients?
tumor spreads early
In Kaposi sarcoma in AIDS patients what is the treatment?
antiretroviral agents (to boost immune system)
What is seen with Kaposi sarcoma in transplant recipients?
tumor spreads early;
For Kaposi sarcoma in transplant recipients what is the treatment?
treatment involves decreasing immunosuppression
