Pathology
Lecture 27 Diseases of the Blood Vessels
1) To know the broad general categories of ateriosclerosis.
Atherosclerosis
Mönckeberg's arteriosclerosis
Arteriosclerosis
2) To know the typical vessels affected by atherosclerosis. Large and medium-sized
muscular arteries (e.g. coronary, carotid) and elastic arteries (e.g. aorta).
3) To be able to characterize the gross and histologic appearance of atheromatous
plaques.
Gross: raised, white to yellow plaques on luminal aspect of artery.
Micro: Fibrous plaques contain a central core of cholesterol and cholesterol esters,
lipid-laden macrophages or foam cells, calcium and necrotic debris. The core is
covered by a subendothelial fibrous cap, made up of smooth muscle cells, foam cells,
fibrin and other coagulation proteins, as well as extracellular matrix material, such as
collagen, elastin, glycosaminoglycans, and proteoglycans.
4) To be familiar with the general theories of pathogenesis of atherosclerosis.
1. Endothelial injury/dysfunction - may stimulate SM proliferation, synthesis of
collagen, elastic fibers, and proteoglycans; endothelial injury may also induce
monocyte migration to the area, with T cell interaction and lipid accumulation.
2. Smooth muscle proliferation - SM cells synthesize extracellular matrix and
accumulated lipids.
3. Macrophages - accumulated lipids, recruit other WBC's into area, oxidize lowdensity lipoprotein and stimulate further SM proliferation.
4. Hyperlipidemia may promote endothelial and smooth muscle cell injury, increases
potential penetration of lipids in plaque and formation of lipid-laden foam cells.
5) To know the complications of atherosclerotic plaques and clinical outcomes of
atherosclerosis.
Complications: narrowing of the arterial lumen, calcification in ulcer of plaque
(thrombi with embolization), hemorrhage into plaque, and weakening of vessel wall
with formation of aneurysm.
Clinical Outcomes: MI/ischemic heart disease, cerebral infarct (stroke), gangrene of
lower extremities, and intestinal infarction.
6) To be familiar with the risk factors and epidemiology of atherosclerosis.
Risk factors include: advanced age, gender (more common men, but increases in
postmenopausal women), genetic predisposition (diabetes, hyperlipidemia, and
hypertension), hyperlipidemia particularly hypercholesterolemia, hypertension,
cigarette smoking, and diabetes. Less firmly established our obesity, physical
inactivity, "Type A" personality with stress factors in lifestyle, hyperuricemia, and
use of oral contraceptive drugs (especially with smoking).
Epidemiology: death rate from ischemic heart disease (primarily due to
atherosclerosis) is much higher in the US than most other Western countries.
7) To be able to characterize the vessels involved with Mönckeberg’s
arteriosclerosis, the types of patients involved, and the microscopic appearance.
Vessels in Mönckeberg's arteriosclerosis are medium to small sized arteries, showing
calcification of media. It is characterized by ring like calcifications and does not
obstruct arterial flow because the intima is not involved Most typically affects the
radial and ulnar arteries. Patients are generally older than 50 years (no gender
preference). Microscopic: selective calcification of media, no inflammation.
8) To know the main types of arteriosclerosis.
1. Hyaline arteriosclerosis - characterized by hyaline thickening of arteriolar walls,
in the kidney it's termed benign nephrosclerosis it is associated with hypertension.
2. Hyperplastic arteriosclerosis - characterized by concentric, laminated,
"onionskin" thickening of arteriolar walls, in the kidney it's termed malignant
nephrosclerosis and is associated with malignant hypertension.
9) For the various types of vasculitis, to be familiar with the following for each
major group:
1. Size of vessels involved.
2. Organ systems most frequently affected.
3. Age and gender predilection.
4. Histologic appearance.
5. Major clinical presenting signs and symptoms.
6. Appropriate diagnostic tests.
Type
Size of
vessels
Small,
medium
arteries
Organ systems
Hypersensitivity
(leukocytoplastic)
Angitis
Very
small
vessels
Skin, lungs, mucous
membranes, brain,
viscera and muscle.
Wegener's
Granulomatosis
Small
arteries
and
veins
Respiratory tract,
kidneys, and other
organs
Middleaged,
males
>females
Temporal
Arteritis
Medium
to small
arteries
Cranial vessels
(especially temporal
artery)
Elderly
females
>males
Polyarthritis
nodosa (PAN)
Kidney, coronary
arteries,
musculoskeletal system,
GI tract, CNS and PNS
Age and
gender
Young
adults to
middleage
Histology
Signs and symptoms
Fibrinoid necrosis
and inflammation
of vessel wall
Renal failure,
ischemic heart
disease, myalgia,
arthralgia, arthritis,
nausea and vomiting,
abdominal pain
Palpable purpura,
Henoch-Schonlein
purpura - arthralgias,
hemorrhagic urticaria
with fever and GI and
renal involvement
Necrotizing
granulomatous
vasculitis, pulmonary
infiltrates, sinusitis,
ulceration of nasal
mucus membranes,
renal abnormalities
(hematuria, renal
failure)
Headache, tenderness
over artery, visual
disturbances, and
facial pain
Neutrophils in
vessel wall
frequently
fragmented
producing "nuclear
dust"
Fibrinoid necrosis,
neutrophil
infiltration,
mononuclear cell
infiltration,
fibrosis, granuloma
formation
Granulomatous
inflammatory
disease
Diagnostic
tests
Biopsy of
affected
organ
Biopsy of
the skin
Nasal/sinus,
renal, and
bronchial
biopsies
Erythrocyte
sed. rate,
temporal
artery
biopsy
10) To know the major types of aneurysms, their etiologies, characteristic antatomic
sites of distribution, presenting clinical complaints and/or clinical outcomes,
mechanism of formation, and histologic appearances.
Type
Atherosclerotic
aneurysms
Syphilitic
aneurysms
Etiology
Atherosclerosis
Inflammatory
reaction
Distribution
Abdominal aorta below
renal arteries above iliacs
Thoracic aorta extending
to aortic valve
Clinical Complaints/Outcomes
Rupture w/hemorrhage, embolism,
compression, occlusion, mass
Symptoms due to compression of
adjacent thoracic structures
Dissecting
aneurysms
Marfan
syndrome
Ascending aorta extends
proximally and distally
Chest pain, occlusion of arterial
branches of aorta, aortic valve
insufficiency, hemorrhage
Mechanism
Vessel
dilation
occlusion of
vaso
vasorum
Dissects
through
intima
11) To be responsible for all material covered in the handout on “Diseases of Blood
Vessels.” Review handout.
Histology
Intimal tear
rupture
Adventitia
inflammation,
media injury
Cystic medial
necrosis,
medial tear