Vascular Pathology Pathoma Only Flashcards
Vasculitis is defined how?
Inflammation of a vessel wall
Wall of the blood vessel is composed of what layers?
Adventitia
Media
Intima
Intima is composed of what?
Endothelial cells sitting on a basement membrane
Adventitia is composed of what?
Connective Tissue
Media is composed of what?
Smooth muscle cells
How involved is infection with most vasculitis cases?
Not involved usually
What types of clinical findings do we see with vasculitis? 2 types
Nonspecific Symptoms
Symptoms of Organ Ischemia
Nonspecific symptoms of vasculitis are involved with what?
Fever, malaise, inflammation, weight loss, etc.
Two ways of getting organ ischemia due to vasculitis:
- Thrombosis - Endothelial cell damaged, causing coagulation cascade from subendothelial collagen and tissue factor, forming a thrombus that blocks up the vessel
- Inflame the wall, healing ensues, you get fibrosis of the wall, thus narrowing the lumen and decreasing blood flow to the organ, causing ischemic changes
Temporal (Giant Cell) Arteritis (TGCA) is most common in who?
Older adults, over the age of 50, females preferentially
Location of TGCAs?
Branches of the Carotid Artery
TGCA that causes headaches?
Temporal artery affected
TGCA that causes visual disturbances?
Opthalmic artery affected
TGCA that causes jaw claudication?
Arteries feeding muscles of the jaw
What other general symptoms doe we see with TGCA?
Flue like symptoms with joint and muscle pain
Lab findings for TGCA
Elevated ESR > 100
TGCA often involves getting a biopsy. What does that biopsy show?
- Inflammed vessel wall
- Giant cells present due to the fact that this is a granulomatous vasculitis
- Intimal fibrosis
TGCA is unique because it involves a long piece of vessel for biopsy. Why?
It’s segmental, not across the whole vessel. Thus a negative finding does not mean you don’t have it AND you have to check the whole thing because it could just be one small segment that is affected
Histological findings of TGCA
- Presence of Giant Cells
- Fibrosis and enlargement of the Intima
- Inflammation
How do we know we are looking at a Giant Cell?
Cell with many nuclei
What is the treatment for TGCA and what happens if we don’t treat it?
High risk of blindness without treatment due to the effects on the opthalmic artery, treat with corticosteroids
What is Takayasu Arteritis and how does it relate to TGCA? Who does it affect?
It’s another Granulomatous Arteritis but it affects adults <50 and is an asian female. Basically the same thing
There are a couple of differences between Takayasu and TGCA. What are they?
- Takayasu is more proximal and involves the aortic arch and its early branches
- Causes more general neurological and visual disturbances
What is Takayasu also called? Why?
Pulseless disease - Weak or absent pulse in the upper extremity
How do treatment and lab tests differ between TGCA and Takayasu?
They don’t. ESR still elevated and you still treat with corticosteroids.
Medium vessel vasculitis affects what types of arteries?
Muscular arteries specifically
Polyarteritis Nodosa (PN) involves what organs? What type of vasculitis is it?
Necrotizing vasculitis involving most organs but the lungs are spared.
Who gets PN?
Young Adults
Symptoms of PN? What arteries are affected in these symptoms?
All kinds of things, but usually:
- HTN (renal artery)
- Abdominal pain with melena (mesenteric artery)
- Neurologic disturbances
- Skin Lesions
PN is associated with serum ______.
HBsAg (Hep B surface Antigen)
There is something unique about PN tht we see on Biopsy. What is it?
“String of pearls”
The disease has various stages and they all appear segmentally along the wall.
What are the stages of Fibrinoid Necrosis (FN)?
Stage 1 - Fibrinoid Necrosis through all layers of the vessel (Transmural - through all layers)
Stage 2 - Fibrosis (healed Fibrinoid Necrosis!) - Vessel feels bumpy (gives name Nodosa)
Where does “String of pearls” come from
Different stages of FN through the vessel. In stage 1, we can get an aneurysm, a ballooning out, due to weakening of the wall from fibrinoid necrosis. This gives the “pearls”
Fibrinoid necrosis looks like what under histology?
Lots of pink! Inflammation also present
Treatment of PN? Penalties of not treating?
Corticosteroids AND Cyclophosphamide
Fatal if not treated
Kawasaki Disease affects who?
Asian kids <4
Presentation of Kawasaki?
Vague, Nonspecific symptoms
- Fever
- Conjunctivitis
- Red rash on palms and soles
- Enlarged cervical lymph nodes
Artery usually involved with Kawasaki? What bad complications (2 of them) are associated with it?
Coronary artery involvement most common.
- Thrombosis with myocardial infarction
- Aneurysm with rupture
Treatment of Kawasaki
Given Aspirin and IVIG
Aspirin is interesting because you don’t give kids Aspirin for viral infections, which this looks a lot like, due to the possibility of Reye’s Syndroms
Why do we give Aspirin for Kawasaki?
Stop platelet aggregation and thus stop Thrombus. Also inhibits TXA2 creation by the platelets.
What is Buerger’s disease
Necrotizing vasculitis of the digits (muscular arteries)
How does Buerger’s present?
Ulceration, gangrene, and autoamputation of fingers and toes
Treatment of Buerger’s?
Highly associated with smoking so stop smoking you idiot
Buerger’s is associated with what phenomenon? Describe it.
Raynaud Phenomenon - Patient gets vasospasm that causes discoloration of fingers and toes due to decreased blood flow to the fingers. White to blue to red with blood restoration.
Wegener Granulomatosius (Wegener’s) is what kind of vasculitis? What does it involve?
Small vessel Necrotizing vasculitis of the nasopharynx, lungs, and kidneys
Wegerner’s is associated with an antibody. What is it? Explai nthe test we use for this
Elevated C-ANCA, which is anti-neutrophil antibody.
You put serum on a test slide that has a neutrophil. It can do nothing, react with the neutrophil nucleus periphery (right around it) indicating P-ANCA or it can react further out in the cytoplasm (C-ANCA)
Treatment of Wegener’s
Cyclophosphamide
Who get’s Wegener’s? How does it present?
Middle aged males
They present with
Nasopharynx - sinusitis or nasopharyngeal ulceration
Lungs - Hemoptysis with bilateral nodular lung infiltrates
Kidneys - Hematuria
What causes the kidney issues seen in Wegener’s?
Rapidly progressing glomerular nephritis causes blood in the urine
Biopsy for Wegener’s
Large necrotizing granulomas with adjacent necrotizing vasculitis
Giant cells can be seen as well
What is Microscopic Polyangiitis (MP) and what does it affect?
Small vessel Necrotizing vasculitis that affects the lung and kidney
Distinguish Wegener’s from MP
Very similar, but MP does not have nasopharyngeal involvement or granulomas, and finally, MP is associated with P-ANCA, not C-ANCA
Treatment of MP?
Cyclophosphamide
Churg-Strauss Syndrome (C-S Syndrome) is what kind of vasculitis? What organs are affected most?
Small vessel necrotizing granulomatous vasculitis with eosinophils.
Lungs and heart
How does C-S Syndrome present in the lungs?
Asthma with peripheral eosinophilia
What lab value is associated with C-S Syndrome?
P-ANCA
3 Features to help you distinguish between MP and C-S Syndrome
Both have P-ANCA, but C-S has asthma, granulomas and peripheral eosinophilia. MP has none of those.
What kind of vasculitis is Henoch Schonlein Purpura (HSP)? What is it most common in?
Vasculitis due to IgA immune complex deposition. It is the most common vasculitis in children!
Presentation of HSP? What does it stand for again?
Henock Schonlein Purpura…
- Palpable purpura on buttocks and legs
- GI pain and bleeding
- Hematuria due to IgA nephropathy
HSP occurs usually after what?
Upper respiratory infection (think of IgA, which protects mucosal sites)
What defines systemic HTN?
Greater than 140/90
What types of HTN can we diagnose?
5% - Secondary HTNs
Renal Artery stenosis is what? What does it cause?
Unilateral atrophy of the affected kidney due to a stenosis of the renal artery off of the Aorta.
In response to the reduced blood flow, the glomerulus releases renin which in turn releases Angiotensin I and via ACE goes to Angiotensin 2, which causes HTN by
- Directly contracting arterioles
- Promoting adrenal release of aldosterone which goes to distal convoluted tubule to retain Na and cause fluid buildup in the blood.
Causes of Renal Artery Stenosis and who they affect the most
- Atherosclerosis - Seen in elderly men
2. Fibromuscular dysplasia - young females
HTN can be defined as benign or malignant.
How does Benign present and what is it?
Mild or moderate elevation in HTN and is clinically silent.
Vessels and organs are damaged over time.
HTN can be defined as benign or malignant.
How does malignant present and what is it? How do you get it?
Severe elevation in BP (>200/120)
May arise from preexisting Benign HTN. Some just get it for no reason.
Present with Acute renal failure, headache and papilledema. MEDICAL EMERGENCY
What are the three pathologic patterns of arteriosclerosis?
- Artherosclerosis
- Arteriolosclerosis
- Monckeberg medial calcific sclerosis
Artherosclerosis is what type of pathology?
Affects intima of vessel walls of medium and large sized vessels. The intimal plaque obstructs blood flow.
Arteriolosclerosis affects what vessels? What types are there?
Affects small vessels due to deposition or increase in protein in the vessel wall (Hyaline arteriolosclerosis) or hyperplasia of smooth muscle (hyperplastic arteriolosclerosis)
Describe Artherosclerosis structurally
- In Intima
- Involves cholesterol buildup with a fibromuscular cap
- Necrotic core that can get calcified
4 most common involved arteries of artherosclerosis?
- Abdominal Aorta
- Coronary
- Popliteal
- Internal Carotid
Modifiable risk factors of artherosclerosis
4 of them
HTN
Hypercholesterolemia
Smoking
Diabetes
Nonmodifiable risk factors of artherosclerosis
3 of them
Age - Older
Gender - Increase in males and post-menopausal females
Genetics
Pathogenesis of artherosclerosis and what findings do we see with it?
Endothelial cell damage with lipid deposition following into the intima, it gets oxidized, eaten by macrophages = foamy cells (fatty streak)
Artherosclerosis can cause stenosis of medium sized vessels. What three are affected the most and what conditions are associated with them?
Popliteal arteries - Peripheral vascular disease
Coronary Artery - Angina
Mesenteric arteries - Ischemic bowel disease
When do you usually see complications with stenosis?
70% occlusion
Plaque rupture with thrombosis can cause major damage in what two ways in artherosclerosis?
Myocardial infarction due to occlusion of the coronary artery
Stroke due to occlusion of the middle cerebral artery
Plaque rupture with embolization results in what? How is it characterized?
Results in artherosclerotic emboli and is characterized by cholesterol clefts in the emboli
How does a plaque cause an aneurysm?
Builds up on the side of the vessel walls and stops oxygen from entering the tissue layers of the vessel itself, starving the walls and causing them to thin and balloon out.
If I see a a thickened pink arteriole, what should I think of?
Hyaline arteriolosclerosis due to protein deposition in the wall.
Who gets Hyaline arteriosclerosis? How?
What group of folks is particularly at risk and why?
Folks with benign HTN. The higher pressuree pushes protein into the walls
Diabetics - Nonenzymatic glycosylation of the membrane of the walls, making them leaky to protein.
What is arteriolonephrosclerosis? What does it progress to and what do the kidneys look like?
Clasically produced glomerular scarring due to hyaline arteriolosclerosis blocking the afferent arterole going to the glomerulus.
Progresses to chronic renal failure. Kidney looks smaller and scarred.
When do we see onion skin vessels? What is happening when we see this? What causes this?
Hyperplastic arteriolosclerosis caused by lots of smooth muscle layers in the arterioles. Caused by Malignant HTN.
In hyperplastic arteriolosclerosis, we can get fibrinoid necrosis of the vessel wall. What other finding do we associate with this pathology?
Flea-bitten appearance after acute renal failure due to lots of small hemorrhages
What do we see witn Monckeberg Medial Calcific Sclerosis? How dangerous is this?
Calcification of the media that is nonobstructive, not clinically significant.
Repeat, it does not affect blood flow AT ALL
Seen as an x-ray or mammography finding
Histology of Monckeberg?
In the Media (unaffected intima) you see areas of calcification.
What is a dissection?
Intimal tear with blood going between the intima and media, tearing the layer off. Causes the blood to eventually leave the vessel by rupturing the media
Aortic dissection requires two things:
- LOT OF STRESS in the blood stream
2. NEED a preexisting weakened media
Where do dissections usually occur?
First 10cm of the proximal aorta
How does the media weaken with HTN in the first 10 cm of the aorta?
First 10 cm is really thick, already hard to get oxygen there. Vaso vasorum in the area helps bring oxygen to it to stop any problems from occurring.
However in HTN, you get hyaline arteriolosclerosis, leading to blockage of the vasovasorum, leading to starving of the media.
How else besides HTN can the media be weakened?
Connective tissue defects, particularly fibrin issues that disrupt elastin deposition (Marfans) or collagen synthesis problems (Ehlers Danlos)
Presentation of dissection
Sharp pain in chest radiating to back
Most common cause of death with dissections?
Pericardial tamponade - gets between the layers and goes backwards to the heart and goes into the pericardium.
But obstruction of vital organ arteries and rupture of the vessel are equally as lethal.
What disease do we typically see associated with Thoracic Aortic Aneurysm? What does the aorta look like with this?
Tertiary Syphillis - Gives tree bark appearance to aorta because the vasovasorum are blocked up and atrophied in the adventitia, weakening the media and thus the wall (endoarteritis)
How can a thoracic aortic aneurysm cause aortic insufficiency?
Dilation of the aortic valve root pushes the valve open due to spreading of the root out, causing insufficiency of the aorta.
(Valve doesn’t close, leading to aortic regurgitation)
What other complications besides aortic insufficiency do we see with thoracic aortic aneurysms?
Mediastinal structure compression and thrombosis/embolism, which causes turbulent flow in the balloon portion of the vessel, leading to coag pathway and creation of a thrombus, which if it detaches, will become an embolus.
Where do AAAs occur? What are they?
This is a balloon dilation of the abdominal aorta which is below the renal arteries and above the aortic bifurcation.
What is different about the etiology of AAA when compared to a TAA?
AAAs involve smokers over the age of 60 and is related to artherosclerosis, this is key because it separates these two.
Recall that TAA happens due to the outside adventitia vaso vasorum being affected, starving the media from the outside in.
In AAA, the plaque build up from Artherosclerosis stops O2 from diffusing into the media, starving it from within the vessel itself.
Presentation of AAA and complications that arise.
- Pulsatile abdominal mass that grows with time
- It can rupture when > 5cm and present with the triad of
1. Hypotension
2. Pulsatile abdominal mass
3. Flank pain
What is a hemangioma? When and with whom does it present? What organs are affected?
Benign tumor comprised of blood vessels, commonly presents at birth and regresses during childhood (so don’t do surgery).
Mostly involves the skin and liver and WILL BLANCHE WITH PALPATION
What is an angiosarcoma? Where do we see it?
Malignant proliferation of endothelial cells lining the blood vessel. Highly aggressive and common sites are the skin, breast, and liver
What exposures are linked to Liver angiosarcoma?
PVC
Arsenic
Thorotrast
What is a Kaposi sarcoma and what is it linked with?
Low grade malignant proliferation of endothelial cells associated with the virus HHV-8
How does Kaposi sarcoma present?
- Purple patches, plaques, or nodules on skin THAT DO NOT BLANCHE ON PALPATION
- May involve visceral organs
Who gets Kaposi? How do you treat them?
- Older Eastern European males - Surgery to remove it
- AIDS - Antiretroviral agents
- Transplant recipients - Usually involves the skin, give decreased immunosuppression to allow immune system to fight the HHV-8 affected endothelial cells
