Vascular Pathology I Flashcards
Both arteries and veins are composed how?
from inside to out, both arteries and veins are composed of an intima, a media, and an anventitia
what level is blood pressure controlled?
at the level of the arteriole
how does a vein’s media differ from an artery’s?
since veins are low pressure, they only have a thin walled media without significant elastic fibers
how do capillaries differ from veins/arteries?
capillaries only have a simple endothelial lining surrounded by pericytes but no media
what is an arteriovenous malformation?
a direct connection of arteries to veins, bypassing capillaries
What do large or multiple AVMs lead to?
they shunt blood from arterial to venous circulation, forcing the heart to pump additional volume leading to high-output cardiac failure
why would an AVM be surgically created?
it provides vascular access for hemodialysis or chemotherapy agents
how might a patient with a superficial AVM of the brain present?
seizure and intracerebral hemorrhage
What is a berry (saccular) aneurysm?
a focal abnormal dilation of an artery due to underlying defect in media
what are the risk factors for berry (saccular) aneurysm?
HTN and smoking
Berry (saccular) aneurysms are associated with what other diseases?
AD polycystic kidney disease, Marfan syndrome, and Ehlers-Danlos syndrome
berry aneurysms can lead to what?
subarrachnoid hemorrhage if they rupture
rupture of a berry aneurysm is associated with that?
acute increases in intracranial pressure like straining with stool or sexual orgasm
what is a mycotic aneurysm?
a dilation of an artery due to damage of the vessel wall by an infectious process
what is fibromuscular dysplasia?
an irregular thickening in muscular arteries caused by medial and intimal hyperplasia
how does fibromuscular dysplasia arise?
thought to be a developmental abnormality, as it has increased incidence in first degree relatives
how does fibromuscular dysplasia appear on angiography?
string of beads appearance
which arteries are most commonly affected by fibromuscular dysplasia and what does this lead to?
the renal arteries–> leads to renal artery stenosis; the renal artery stenosis causes low volume of blood flow to the kidney which activates the renin, angiotensis, aldosterone system
what kidney diseases could lead to secondary HTN?
renovascular disease, renal artery stenosis (caused by fibromuscular dysplasia or atherosclerosis) or polycystic kidney disease
what endocrine disease could lead to secondary HTN?
primary aldosteronism, cushing syndrome, or pheochromocytoma
what cardiovascular diseases could lead to secondary HTN?
coarctation of the aorta
how does primary aldosteronism present?
HTN and hypokalemia
if a patient is hypokalemic, how might they present?
weakness, muscle cramps, paresthesias, and visual disturbances
what is usually the cause of primary hyperaldosteronism?
bilateral nodular hyperplasia of the adrenal gland
what effect does aldosterone have on the body?
it reabsorbs sodium and excretes potassium leading to HTN and hypokalemia
what causes cushing syndrome?
increased cortisol production by the adrenal gland
what is a pheochromacytoma?
a tumor of chromaffin cells of the adrenal medulla
what does a pheochromocytoma secrete?
catecholamines including epinephrine and norepinephrine
besides HTN, what are the other associated features of a pheochromocytoma?
it can induce paroxysms of elevated BP associated with tachycardia, palpitation, HA, diaphoresis, tremor
what are pheochromocytomas associated with?
MEN 2 syndromes
how would you test for a pheochromocytoma?
test urinary or plasma metanephrines (they’ll be elevated)
what is the adult form of coarctation of the aorta?
there’s a congenital narrowing or infolding of the aorta opposite the ligamentum arteriosum
what effect does coarctation of the aorta have on the body?
HTN in the UEs with weak pulses and hypotension in the LEs
what is coarctation of the aorta associated with?
bicuspid aortic valve
what effect does mild to moderate chronic hypertensive disease have on the small arterioles?
hyaline arteriolosclerosis
what is hyaline arteriolosclerosis?
there is arteriolar narrowing- the hyaline material is compromised of precipitated plasma proteins
what happens in hyaline nephrosclerosis?
there is narrowing–> impairment of the renal blood supply and ischemic glomerulosclerosis
what is the definition of a hypertensive crisis?
a rapid increase in BP: systolic >180-200 and diastolic >120
what is a hypertensive emergency?
a hypertensive crisis with end organ damage
what is hyperplastic arteriolosclerosis?
occurs in severe HTN, the pressure induces the artery to produce lamellated, thickening of the walls–> smooth muscle forms concentric lamellations showing an “onion skinning” pattern
the gross findings of a kidney in long standing HTN correspond with what?
hyaline arteriolosclerosis with characteristic pink amorphous change
what are the gross findings in a kidney in a case of rapidly increasing BP?
numerous petechial hemorrhages–> hyperplastic arteriolosclerosis
what is myocardial vessel vasospasm?
excessive vasoconstriction of myocardial arteries or arterioles which could cause ischemia or infarct
what are 3 causes of myocardial vascular contraction (vasospasm)?
1) high levels of vasoactive mediators 2) elevated thyroid hormones 3) autoantibodies and T cells in scleroderma
what are 3 examples of vasoactive mediators that can cause myocardial vascular contraction (vasospasm)?
cocaine, epinephrine, and norepinephrine
what is Takotsubo cardiomyopathy?
“broken heart syndrome”- severe emotional distress can cause an overwhelming release of catecholamines stimulating increased contractility and constriction of coronary arteries–> can lead to ischemic cardiomyopathy
what are varicose veins?
abnormally dilated, twisted veins which occur from prolonged increased intraluminal pressure leading to incompetence of venous valves and dilation of the veins
what can varicose veins lead to?
stasis, congestion, thrombus, edema, pain, and ischemia of overlying skin (stasis dermatitis)
what does portal hypertension lead to?
esophageal varices, splenomegaly, hemorrhoids, and caput medusae
what is the most common cause of superior vena cava syndrome?
intrathoracic malignancy–> bronchogenic lung carcinoma and lymphoma
how does superior vena cava syndrome present?
marked dilation of veins of head, neck, chest wall, arms with cyanosis; facial swelling, neurologic manifestations, respiratory distress
what is the most common cause of inferior vena cava syndrome?
neoplasms- especially hepatocellular carcinoma and renal cell carcinoma
how does inferior vena cava syndrome present?
lower extremity edema and distention of the superficial collateral veins of the lower abdomen
what is thrombophelitis?
a venous thrombosis and inflammation
what cases are paradoxical emboli seen?
ventricular septal defect, PDA, and AV malformations
lymphangitis is usually caused by what?
beta-hemolytic streptococcus
what is a cause of primary lymphedema?
congenital defect- familial milroy disease (lymphatic agenesis)
what is peau d’orange?
in breast cancer, when draining lymphatics fill with tumor, one can see distinctive pitting or dimpling texture
What is vascular ectasias? and what are 2 examples?
local dilation of a blood vessel; nevus simplex and port-wine stain
what is sturge-weber syndrome?
rare disorder characterized by a facial port wine stain with associated additional capillary venous malformations that affect the brain and the eye
what is a prototypical clinical presentation of sturge-weber syndrome?
a large facial telangiectasia in a child with mental deficiency
what causes sturge-weber syndrome?
somatic mutations in fetal ectodermal tissue causing inappropriate maturation of blood vessel formation- so its not heritable
when are spider telangiectasias commonly seen?
in cases of increased circulating estrogen–> pregnancy or liver disease
what is osler-weber-rendu syndrome?
an autosomal dominant disorder in which numerous telangiectasias and AV malformations form throughout the body
what mutation is associated with osler-weber-rendu disease?
mutation in TGF-beta signaling pathway
what occurs when the TGF-beta pathway is mutated?
abnormal blood vessel formation in the skin, mucous membranes, and organs
what is a hemangioma?
common, benign vascular tumor of children and adults
when internal involvement of hemangiomas is present, where are they likely found?
liver
what is a cavernous hemangioma?
an irregular dilated vascular channel making a lesion with an indistinct border; more likely to involve deep tissue and more likely to bleed
what is the histologic appearance of a cavernous hemangioma?
it has enlarged vascular spaces filled with blood
what is a glomus tumor?
a mesenchymal tumor composed of modified smooth muscle arising from glomus body responsible for thermoregulation
what are the characteristics of a glomus tumor?
bluish tumor with a predilection for the subungal location under the fingernail; painful and gets worse with temperature changes
what are the 2 principal types of lymphangioma?
1) simple (capillary) lymphangioma and 2) cavernous lymphangioma
what is the key difference between hemangiomas and capillary lymphangiomas?
in capillary lymphangiomas, the dilated spaces do not contain RBCs
what is a cavernous lymphangioma?
thought to arise from a congenital malformation where the lymphatics fail to communicate with the venous system
what are cavernous lymphangiomas associated with?
turner syndrome
What is bacillary angiomatosis?
a reactive vascular proliferation to gram negative bartonella bacilli- occurs in immunocompromised
what are the microscopic features of bacillary angiomatosis?
lobular proliferation of capillaries and ectatic vessels lined by endothelial cells typically with background inflammatory cells; bacteria on silver stain
what is kaposi sarcoma?
an angioproliferative disorder caused by HHV 8
what are the 4 types of kaposi sarcoma?
classic, endemic (africa), iatrogenic, and AIDS
all 4 subtypes of kaposi sarcoma can show 3 distinct stages on the skin- what are they?
1) patch 2) plaque 3) tumor
what are 3 important risk factors for angiosarcoma?
1) liver angiosarcoma: arsenic, thortrast, and PVC production 2) lymphedema- s/p axillary lymph node dissection–> lymphgosarcoma 3) radiation for carcinoma
what do angiosarcomas stain for?
CD31 or CD34
