U2-Robbins-C11: Vasculitis Flashcards Preview

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Flashcards in U2-Robbins-C11: Vasculitis Deck (39)
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1

The development of atheromatous plaque formation with subsequent complications is observed in an experiment.

Atherosclerotic plaques are shown to change slowly but constantly in ways that can promote clinical events, including

acute coronary syndromes. In some cases, changes occurred that were not significantly associated with acute coronary

syndromes. Which of the following plaque alterations is most likely to have such an association?

□ (A) Thinning of the media

□ (B) Ulceration of the plaque surface

□ (C) Thrombosis

□ (D) Hemorrhage into the plaque substance

□ (E) Intermittent platelet aggregatio

(A) Atheromatous plaques can be complicated by various pathologic alterations, including hemorrhage, ulceration,

thrombosis, and calcification. These processes can increase the size of the plaque and narrow the residual arterial lumen.

Although atherosclerosis is a disease of the intima, in advanced disease, the expanding plaque compresses the media.

This causes thinning of the media, which weakens the wall and predisposes it to aneurysm formation.

2

A 60-year-old woman has reported increasing fatigue over the past year. Laboratory studies show a serum creatinine

level of 4.7 mg/dL and urea nitrogen level of 44 mg/dL. An abdominal ultrasound scan shows that her kidneys are

symmetrically smaller than normal. The high-magnification microscopic appearance of the kidneys is shown in the figure.

These findings are most likely to indicate which of the following underlying conditions?

□ (A) Escherichia coli septicemia

□ (B) Systemic hypertension

□ (C) Adenocarcinoma of the colon

□ (D) Tertiary syphilis

□ (E) Polyarteritis nodosa

(B) The figure shows an arteriole with marked hyaline thickening of the wall, indicative of hyaline arteriolosclerosis.

Diabetes mellitus also can lead to this finding. Sepsis can produce disseminated intravascular coagulopathy with arteriolar

hyaline thrombi. The debilitation that accompanies cancer tends to diminish the vascular disease caused by atherosclerosis. Syphilis can cause a vasculitis involving the vasa vasorum of the aorta. Polyarteritis can involve large to

medium-sized arteries in many organs, including the kidneys; the affected vessels show fibrinoid necrosis and

inflammation of the wall (vasculitis).

3

A 55-year-old woman visits her physician for a routine health maintenance examination. On physical examination, her

temperature is 36.8°C, pulse is 70/min, respirations are 14/min, and blood pressure is 160/105 mm Hg. Her lungs are clear

on auscultation, and her heart rate is regular. She feels fine and has had no major medical illnesses or surgical

procedures during her lifetime. An abdominal ultrasound scan shows that the left kidney is smaller than the right kidney. A

renal angiogram shows a focal stenosis of the left renal artery. Which of the following laboratory findings is most likely to

be present in this patient?

□ (A) Anti–double-stranded DNA titer 1 : 512

□ (B) C-ANCA titer 1 : 256

□ (C) Cryoglobulinemia

□ (D) Plasma glucose level 200 mg/dL

□ (E) HIV test positive

□ (F) Plasma renin 15 mg/mL/hr

□ (G) Serologic test for syphilis positive

(F) This is a classic example of a secondary form of hypertension for which a cause can be determined. In this case, the

renal artery stenosis reduces glomerular blood flow and pressure in the afferent arteriole, resulting in renin release by

juxtaglomerular cells. The renin initiates angiotensin II–induced vasoconstriction, increased peripheral vascular resistance,

and increased aldosterone, which promotes sodium reabsorption in the kidney, resulting in increased blood volume. Anti–

double-stranded DNA is a specific marker for systemic lupus erythematosus. ANCAs are markers for some forms of

vasculitis, such as microscopic polyangiitis or Wegener granulomatosis. Some patients with hepatitis B or C infection can

develop a mixed cryoglobulinemia with a polyclonal increase in IgG. Renal involvement in such patients is common, and

cryoglobulinemic vasculitis then leads to skin hemorrhages and ulceration. Hyperglycemia is a marker for diabetes

mellitus, which accelerates the atherogenic process and can involve the kidneys, promoting the development of

hypertension. HIV infection is not related to hypertension. Tertiary syphilis can produce endaortitis and aortic root dilation,

but hypertension is not a likely sequela.

4

A 7-year-old child has had abdominal pain and dark urine for 10 days. Physical examination shows purpuric skin lesions

on the trunk and extremities. Urinalysis shows hematuria and proteinuria. Serologic test results are negative for P-ANCAs

and C-ANCAs. A skin biopsy specimen shows necrotizing vasculitis of small dermal vessels. A renal biopsy specimen

shows immune complex deposition in glomeruli, with some IgA-rich immune complexes. Which of the following is the most

likely diagnosis?

□ (A) Giant cell arteritis

□ (B) Henoch-Schönlein purpura

□ (C) Polyarteritis nodosa

□ (D) Takayasu arteritis

□ (E) Telangiectasias

□ (F) Wegener granulomatosis

(B) In children, Henoch-Schönlein purpura is the multisystemic counterpart of the IgA nephropathy seen in adults. The

immune complexes formed with IgA produce the vasculitis that affects mainly arterioles, capillaries, and venules in skin,

gastrointestinal tract, and kidney. In older adults, giant-cell arteritis is seen in external carotid branches, principally the

temporal artery unilaterally. Polyarteritis nodosa is seen most often in small muscular arteries and sometimes veins, with

necrosis and microaneurysm formation followed by scarring and vascular occlusion. This occurs mainly in the kidney,

gastrointestinal tract, and skin of young to middle-aged adults. Takayasu arteritis is seen mainly in children and involves

the aorta (particularly the arch) and branches such as coronary and renal arteries, with granulomatous inflammation,

aneurysm formation, and dissection. Telangiectasias are small vascular arborizations seen on skin or mucosal surfaces.

Wegener granulomatosis, seen mainly in adults, involves small arteries, veins, and capillaries and causes mixed

inflammation and necrotizing and non-necrotizing granulomatous inflammation with geographic necrosis surrounded by

palisading epithelioid macrophages and giant cells.

5

A 30-year-old woman has had coldness and numbness in her arms and decreased vision in the right eye for the past 5

months. On physical examination, she is afebrile. Her blood pressure is 100/70 mm Hg. Radial pulses are not palpable, but

femoral pulses are strong. She has decreased sensation and cyanosis in her arms, but no warmth or swelling. A chest

radiograph shows a prominent border on the right side of the heart and prominence of the pulmonary arteries. Laboratory

studies show serum glucose, 74 mg/dL; creatinine, 1 mg/dL; total serum cholesterol, 165 mg/dL; and negative ANA test

result. Her condition remains stable for the next year. Which of the following is the most likely diagnosis?

□ (A) Aortic dissection

□ (B) Kawasaki disease

□ (C) Microscopic polyangiitis

□ (D) Takayasu arteritis

□ (E) Tertiary syphilis

□ (F) Thromboangiitis obliterans

(D) Takayasu arteritis leads to “pulseless disease” because of involvement of the aorta (particularly the arch) and

branches such as coronary, carotid, and renal arteries, with granulomatous inflammation, aneurysm formation, and

dissection. Fibrosis is a late finding, and the pulmonary arteries also can be involved. Aortic dissection is an acute problem

that, in older adults, is driven by atherosclerosis and hypertension, although this patient is within the age range for

complications of Marfan syndrome, which causes cystic medial necrosis of the aorta. Kawasaki disease affects children

and is characterized by an acute febrile illness, coronary arteritis with aneurysm formation and thrombosis, skin rash, and

lymphadenopathy. Microscopic polyangiitis affects arterioles, capillaries, and venules with a leukocytoclastic vasculitis that

appears at a similar stage in multiple organ sites (in contrast to classic polyarteritis nodosa, which causes varying stages

of acute, chronic, and fibrosing lesions in small to medium-sized arteries). Tertiary syphilis produces an endaortitis with

proximal aortic dilation. Thromboangiitis obliterans (Buerger disease) affects small to medium-sized arteries of the

extremities and is strongly associated with smoking.

6

A 61-year-old man had a myocardial infarction 1 year ago, which was the first major illness in his life. He now wants to

prevent another myocardial infarction and is advised to begin a program of exercise and to change his diet. A reduction in

the level of which of the following serum laboratory findings 1 year later would best indicate the success of this diet and

exercise regimen?

□ (A) Cholesterol

□ (B) Glucose

□ (C) Potassium

□ (D) Renin

□ (E) Calcium

(A) Reducing cholesterol, particularly LDL cholesterol, with the same or increased HDL cholesterol level, indicates a

reduced risk of atherosclerotic complications. Atherosclerosis is multifactorial, but modification of diet (i.e., reduction in

total dietary fat and cholesterol) with increased exercise is the best method of reducing risk for most individuals. Glucose is

a measure of control of diabetes mellitus. Potassium, calcium, and renin values can be altered with some forms of

hypertension, one of several risk factors for atherosclerosis

7

A 23-year-old man experiences sudden onset of severe, sharp chest pain. On physical examination, his temperature is

36.9°C, and his lungs are clear on auscultation. A chest radiograph shows a widened mediastinum. Transesophageal

echocardiography shows a dilated aortic root and arch, with a tear in the aortic intima 2 cm distal to the great vessels. The

representative microscopic appearance of the aorta with elastic stain is shown in the figure. Which of the following is the

most likely cause of these findings?

□ (A) Scleroderma

□ (B) Diabetes mellitus

□ (C) Systemic hypertension

□ (D) Marfan syndrome

□ (E) Wegener granulomatosis

□ (F) Takayasu arteritis

(D) This is a description of cystic medial degeneration, which weakens the aortic media and predisposes to aortic

dissection. In a young patient such as this, a heritable disorder of connective tissues, such as Marfan syndrome, must be

strongly suspected. Scleroderma and Wegener granulomatosis do not typically involve the aorta. Atherosclerosis

associated with diabetes mellitus and hypertension are risk factors for aortic dissection, although these are seen at an

older age. Takayasu arteritis is seen mainly in children and involves the aorta (particularly the arch) and branches such as the coronary and renal arteries, causing granulomatous inflammation, aneurysm formation, and dissection

8

A 40-year-old man with a history of diabetes mellitus has had worsening abdominal pain for the past week. On physical

examination, his vital signs are temperature, 36.9°C; pulse, 77/min; respirations, 16/min; and blood pressure,

140/90 mm Hg. An abdominal CT scan shows the findings in the figure. Laboratory studies show his hemoglobin A1C is

10.5%. Which of the following is the most likely underlying disease process in this patient?

□ (A) Polyarteritis nodosa

□ (B) Obesity

□ (C) Diabetes mellitus

□ (D) Systemic lupus erythematosus

□ (E) Syphilis

(C) This patient has an atherosclerotic abdominal aortic aneurysm. His abdominal CT scan shows a 6-cm fusiformshaped

enlargement of the abdominal aorta. Diabetes mellitus, an important risk factor for atherosclerosis, must be

suspected if a younger man or premenopausal woman has severe atherosclerosis. His hemoglobin A1C value is consistent

with poorly controlled diabetes mellitus. Polyarteritis nodosa does not typically involve the aorta. Obesity, a “soft” risk

factor for atherosclerosis, also contributes to diabetes mellitus type 2; however, the extent of atherosclerotic disease in this

patient suggests early-onset diabetes mellitus, which is more likely to be type 1. Systemic lupus erythematosus produces

small arteriolar vasculitis. Syphilitic aortitis, a feature of tertiary syphilis, most often involves the thoracic aorta, but it is

rare, and most thoracic aortic aneurysms nowadays are likely to be caused by atherosclerosis

9

A 10-year-old boy is brought to the physician for a routine health maintenance examination. The physician notes a 2-cm spongy, dull red, circumscribed lesion on the upper outer left arm. The parents state that this lesion has been present

since infancy. The lesion is excised, and its microscopic appearance is shown in the figure. Which of the following is the

most likely diagnosis?

□ (A) Kaposi sarcoma

□ (B) Angiosarcoma

□ (C) Lymphangioma

□ (D) Telangiectasia

□ (E) Hemangioma

(E) The figure shows dilated, endothelium-lined spaces filled with RBCs. The circumscribed nature of this lesion and its

long, unchanged course suggest its benign nature. Kaposi sarcoma is uncommon in its endemic form in childhood, and it

is best known as a neoplastic complication associated with HIV infection. Angiosarcomas are large, rapidly growing

malignancies in adults. Lymphangiomas, seen most often in children, tend to be more diffuse and are not blood-filled. A

telangiectasia is a radial array of subcutaneous dilated arteries or arterioles surrounding a central core that can pulsate

10

A pharmaceutical company is developing an antiatherosclerosis agent. An experiment investigates mechanisms of

action of several potential drugs to determine their efficacy in reducing atheroma formation. Which of the following

mechanisms of action is likely to have the most effective antiatherosclerotic effect?

□ (A) Inhibits PDGF/Inhibits macrophage-mediated lipoprotein oxidation

□ (B) Inhibits PDGF/Promotes macrophage-mediated lipoprotein oxidation

□ (C) Promotes PDGF/Promotes macrophage-mediated lipoprotein oxidation

□ (D) Decreases HDL/Inhibits macrophage-mediated lipoprotein oxidation

□ (E) Increases HDL/Promotes macrophage-mediated lipoprotein oxidation

□ (F) Decreases ICAM-1/Promotes macrophage-mediated lipoprotein oxidation

□ (G) Increases ICAM-1/Inhibits macrophage-mediated lipoprotein oxidation

(A) Atherosclerosis is considered a complex reparative response that follows endothelial cell injury.

Hypercholesterolemia (high LDL cholesterol level) is believed to cause subtle endothelial injury. The oxidation of LDL by

macrophages or endothelial cells has many deleterious effects. Oxidized LDL is chemotactic for circulating monocytes,

causes monocytes to adhere to endothelium, stimulates release of growth factors and cytokines, and is cytotoxic to

smooth muscle cells and endothelium. Smooth muscle proliferation in response to injury, important in the development of

atheromas, is driven by growth factors, including platelet-derived growth factor. HDL is believed to mobilize cholesterol

from developing atheromas; high HDL levels are protective. Intercellular adhesion molecule-1 (ICAM-1) and vascular cell

adhesion molecule-1 (VCAM-1) are adhesion molecules on endothelial cells that promote adhesion of monocytes to the

site of endothelial injury.

11

A 73-year-old man who has had progressive dementia for the past 6 years dies of bronchopneumonia. Autopsy shows

that the thoracic aorta has a dilated root and arch, giving the intimal surface a “tree-bark” appearance. Microscopic

examination of the aorta shows an obliterative endarteritis of the vasa vasorum. Which of the following laboratory findings

is most likely to be recorded in this patient's medical history?

□ (A) High double-stranded DNA titer

□ (B) P-ANCA positive 1 : 1024

□ (C) Sedimentation rate 105 mm/hr

□ (D) Ketonuria 4+

□ (E) Antibodies against Treponema pallidum

(E) This description is most suggestive of syphilitic aortitis, a complication of tertiary syphilis, with characteristic

involvement of the thoracic aorta. Obliterative endarteritis is not a feature of other forms of vasculitis. High-titer doublestranded

DNA antibodies are diagnostic of systemic lupus erythematosus, and the test result for P-ANCA is positive in

various vasculitides, including microscopic polyangiitis. A high sedimentation rate is a nonspecific marker of inflammatory

diseases. Ketonuria can occur in individuals with diabetic ketoacidosis

12

For the past 3 weeks, a 70-year-old woman has been bedridden while recuperating from a bout of viral pneumonia

complicated by bacterial pneumonia. Physical examination now shows some swelling and tenderness of the right leg,

which worsens when she raises or moves the leg. Which of the following terms best describes the condition involving the

patient's right leg?

□ (A) Lymphedema

□ (B) Disseminated intravascular coagulopathy

□ (C) Thrombophlebitis

□ (D) Thromboangiitis obliterans

□ (E) Varicose veins

(C) Thrombophlebitis is a common problem that results from venous stasis. There is little or no inflammation, but the

term is well established. Lymphedema takes longer than 3 weeks to develop and is not caused by bed rest alone.

Disseminated intravascular coagulopathy more often results in hemorrhage, and edema is not the most prominent

manifestation. Thromboangiitis obliterans is a rare form of arteritis that results in pain and ulceration of extremities.

Varicose veins are superficial and can thrombose, but they are not related to bed rest

13

A 49-year-old man is feeling well when he visits his physician for a routine health maintenance examination for the first

time in 20 years. On physical examination, his vital signs are temperature, 37°C; pulse, 73/min; respirations, 14/min; and

Robbins & Cotran Review of Pathology Pg. 200

time in 20 years. On physical examination, his vital signs are temperature, 37°C; pulse, 73/min; respirations, 14/min; and

blood pressure, 155/95 mm Hg. He has had no serious medical problems and takes no medications. Which of the following

is most likely to be the primary factor in this patient's hypertension?

□ (A) Increased catecholamine secretion

□ (B) Renal retention of excess sodium

□ (C) Gene defects in aldosterone metabolism

□ (D) Renal artery stenosis

□ (E) Increased production of atrial natriuretic factor

(B) This patient has essential hypertension (no obvious cause for his moderate hypertension). Renal retention of

excess sodium, which is thought to be important in initiating this form of hypertension, leads to increased intravascular fluid

volume, increase in cardiac output, and peripheral vasoconstriction. Increased catecholamine secretion (as can occur in

pheochromocytoma), gene defects in aldosterone metabolism, and renal artery stenosis all can cause secondary

hypertension. Hypertension secondary to all causes is much less common, however, than essential hypertension.

Increased production of atrial natriuretic factor reduces sodium retention and reduces blood volume.

14

A 50-year-old man has a 2-year history of angina pectoris that occurs during exercise. On physical examination, his

blood pressure is 135/75 mm Hg, and his heart rate is 79/min and slightly irregular. Coronary angiography shows a fixed

75% narrowing of the anterior descending branch of the left coronary artery. Which of the following types of cells is the

initial target in the pathogenesis of this arterial lesion?

□ (A) Monocytes

□ (B) Smooth muscle cells

□ (C) Platelets

□ (D) Neutrophils

□ (E) Endothelial cells

(E) Atherogenesis can be considered a chronic inflammatory response of the arterial wall to endothelial injury. The injury promotes participation by monocytes, macrophages, and T lymphocytes. Smooth muscle cells are stimulated to

proliferate. Platelets adhere to areas of endothelial injury. Neutrophils are not a part of atherogenesis, although they can

be seen in various forms of vasculitis. The process begins with endothelial cell alteration.

15

A study of atheroma formation leading to atherosclerotic complications evaluates potential risk factors for relevance in a

population. Three factors are found to play a significant role in the causation of atherosclerosis: smoking, hypertension,

and hypercholesterolemia. These factors are analyzed for their relationship to experimental models for atherogenesis.

Which of the following events is the most important direct biologic consequence of these factors?

□ (A) Endothelial injury and its sequelae

□ (B) Conversion of smooth muscle cells to foam cells

□ (C) Alterations of hepatic lipoprotein receptors

□ (D) Inhibition of LDL oxidation

□ (E) Alterations of endogenous factors regulating vasomotor tone

(A) Atherosclerosis is thought to result from a form of endothelial injury and the subsequent chronic inflammation and

repair of the intima. All risk factors, including smoking, hyperlipidemia, and hypertension, cause biochemical or mechanical

injury to the endothelium. Formation of foam cells occurs after the initial endothelial injury. Although lipoprotein receptor

alterations can occur in some inherited conditions, these account for only a fraction of cases of atherosclerosis, and other

lifestyle conditions do not affect their action. Inhibition of LDL oxidation should diminish atheroma formation. Vasomotor

tone does not play a major role in atherogenesis.

16

A 55-year-old woman has noted the increasing prominence of unsightly dilated superficial veins over both lower legs for

the past 5 years. Physical examination shows temperature of 37°C, pulse of 70/min, respirations of 14/min, and blood

pressure of 125/85 mm Hg. There is no pain, swelling, or tenderness in either lower leg. Which of the following

complications is most likely to occur as a consequence of this condition?

□ (A) Stasis dermatitis

□ (B) Gangrenous necrosis of the lower legs

□ (C) Pulmonary thromboembolism

□ (D) Disseminated intravascular coagulation

□ (E) Atrophy of the lower leg muscles

(A) Venous stasis results in hemosiderin deposition and dermal fibrosis, with brownish discoloration and skin

roughening. Focal ulceration can occur over the varicosities, but extensive gangrene similar to that seen in arterial

atherosclerosis does not occur. The varicosities involve only the superficial set of veins, which can thrombose, but are not

the source of thromboemboli, as are the larger, deep leg veins. The thromboses in superficial leg veins do not lead to

disseminated intravascular coagulopathy. The varicosities do not affect muscle; however, lack of muscular support for

veins to “squeeze” blood out for venous return can predispose to formation of varicose veins.

17

A 35-year-old man is known to have been HIV-positive for the past 10 years. Physical examination shows several skin

lesions with the appearance shown in the figure. These lesions have been slowly increasing for the past year. Which of

the following infectious agents is most likely to play a role in the development of these skin lesions?

□ (A) Human herpesvirus-8

□ (B) Epstein-Barr virus

□ (C) Cytomegalovirus

□ (D) Hepatitis B virus

□ (E) Adenovirus

(A) Human herpesvirus-8 has been associated with Kaposi sarcoma and can be acquired as a sexually transmitted

disease. Kaposi sarcoma is a complication of AIDS. Individuals with HIV infection can be infected with various viruses,

including Epstein-Barr virus (EBV) and cytomegalovirus (CMV), but these have no etiologic association with Kaposi

sarcoma. EBV is a factor in the development of non-Hodgkin lymphoma, and CMV can cause colitis or retinitis or can be

disseminated. Hepatitis B virus can be seen in HIV-infected patients as well, particularly patients with a risk factor of

injection drug use. Adenovirus, which, although rare, can be seen in HIV-infected individuals, tends to be a respiratory or

gastrointestinal infection.

18

A 50-year-old man complains of a chronic cough that has persisted for the past 18 months. Physical examination shows

nasopharyngeal ulcers, and the lungs have diffuse crackles bilaterally on auscultation. Laboratory studies include a serum

urea nitrogen level of 75 mg/dL and a creatinine concentration of 6.7 mg/dL. Urinalysis shows 50 RBCs per high-power

field and RBC casts. His serologic titer for C-ANCA is elevated. A chest radiograph shows multiple, small, bilateral

pulmonary nodules. A nasal biopsy specimen shows mucosal and submucosal necrosis and necrotizing granulomatous

inflammation. A transbronchial lung biopsy specimen shows a vasculitis involving the small peripheral pulmonary arteries

and arterioles. Granulomatous inflammation is seen within and adjacent to small arterioles. Which of the following is the

most likely diagnosis?

□ (A) Fibromuscular dysplasia

□ (B) Glomus tumors

□ (C) Granuloma pyogenicum

□ (D) Hemangiomas

□ (E) Kaposi sarcoma

□ (F) Polyarteritis nodosa

□ (G) Takayasu arteritis

□ (H) Wegener granulomatosis

(H) Wegener granulomatosis is a form of hypersensitivity reaction to an unknown antigen characterized by necrotizing

granulomatous inflammation that typically involves the respiratory tract, small to medium-sized vessels, and glomeruli,

although many organ sites may be affected; pulmonary and renal involvement can be life-threatening. C-ANCAs are found

in more than 90% of cases. Fibromuscular dysplasia is a hyperplastic medial disorder, usually involving renal and carotid

arteries; on angiography, it appears as a “string of beads” caused by thickened fibromuscular ridges adjacent to less

involved areas of the arterial wall. Glomus tumors are usually small peripheral masses. Granuloma pyogenicum is an

inflammatory response that can produce a nodular mass, often on the gingiva or the skin. Hemangiomas are typically

small, solitary, red nodules that can occur anywhere. Kaposi sarcoma can produce plaquelike to nodular masses that are

composed of irregular vascular spaces lined by atypical-appearing endothelial cells; skin involvement is most common, but

visceral organ involvement can occur. Polyarteritis nodosa most often involves small muscular arteries, and sometimes

veins; it causes necrosis and microaneurysm formation followed by scarring and vascular occlusion, mainly in the kidney,

gastrointestinal tract, and skin of young to middle-aged adults. Takayasu arteritis is seen mainly in children and involves

the aorta (particularly the arch) and branches such as the coronary and renal arteries, with granulomatous inflammation,

aneurysm formation, and dissection. Telangiectasias are small vascular arborizations seen on skin or mucosal surfaces.

19

While cleaning debris out of the gate in an irrigation canal, a 50-year-old man cuts his right index finger on a sharp

metal shard. The cut stops bleeding within 3 minutes, but 6 hours later he notes increasing pain in the right arm and goes

to his physician. On physical examination, his temperature is 38°C. Red streaks extend from the right hand to the upper

arm, and the arm is swollen and tender when palpated. Multiple tender lumps are noted in the right axilla. A blood culture

grows group A hemolytic streptococci. Which of the following terms best describes the process that is occurring in this

patient's right arm?

□ (A) Capillaritis

□ (B) Lymphangitis

□ (C) Lymphedema

□ (D) Phlebothrombosis

□ (E) Polyarteritis nodosa

Robbins & Cotran Review of Pathology Pg. 202

□ (F) Thrombophlebitis

□ (G) Varices

(B) The red streaks represent lymphatic channels through which an acute infection drains to axillary lymph nodes, and

these drain to the right lymphatic duct and into the right subclavian vein (lymphatics from the lower body and left upper

body drain to the thoracic duct). Capillaritis is most likely to be described in the lungs. Lymphedema occurs with blockage

of lymphatic drainage and develops over a longer period without significant acute inflammation. Phlebothrombosis and

thrombophlebitis describe thrombosis in veins with stasis and inflammation, typically in the pelvis and lower extremities.

Polyarteritis involves small to medium-sized muscular arteries, typically the renal and mesenteric branches. Varices are

veins dilated from blockage of venous drainage

20

An experiment studies early atheromas. Lipid streaks on arterial walls are examined microscopically and biochemically

to determine their cellular and chemical constituents and the factors promoting their formation. Early lesions show

increased attachment of monocytes to endothelium. The monocytes migrate subendothelially and become macrophages;

these macrophages transform themselves into foam cells. Which of the following is most likely to produce these effects?

□ (A) C-reactive protein

□ (B) Homocysteine

□ (C) Lp(a)

□ (D) Oxidized LDL

□ (E) Platelet-derived growth factor

□ (F) VLDL

(D) Oxidized LDL can be taken up by a special “scavenger” pathway in macrophages; it also promotes monocyte

chemotaxis and adherence. Macrophages taking up the lipid become foam cells that begin to form the fatty streak.

Smoking, diabetes mellitus, and hypertension all promote free radical formation, and free radicals increase degradation of

LDL to its oxidized form. About one third of LDL is degraded to the oxidized form; a higher LDL level increases the amount

of oxidized LDL available for uptake into macrophages. C-reactive protein is a marker for inflammation, which can increase

with more active atheroma and thrombus formation and predicts a greater likelihood of acute coronary syndromes.

Increased homocysteine levels promote atherogenesis through endothelial dysfunction. Lp(a), an altered form of LDL that

contains the apo B-100 portion of LDL linked to apo A, promotes lipid accumulation and smooth muscle cell proliferation.

Platelet-derived growth factor promotes smooth muscle cell proliferation. VLDL is formed in the liver and transformed in

adipose tissue and muscle to LDL.

21

A 12-year-old boy died of complications of acute lymphocytic leukemia. The gross appearance of the aorta at autopsy

is shown in the figure. Histologic examination of the linear pale marking is most likely to show which of the following

features?

□ (A) Cap of smooth muscle cells overlying a core of lipid debris

□ (B) Collection of foam cells with necrosis and calcification

□ (C) Granulation tissue with a lipid core and areas of hemorrhage

□ (D) Lipid-filled foam cells and small numbers of T lymphocytes

□ (E) Cholesterol clefts surrounded by proliferating smooth muscle cells and foam cells

(D) The slightly raised, pale lesions shown in the figure are called fatty streaks and are seen in the aorta of almost all

children older than 10 years. They are thought to be precursors of atheromatous plaques. T cells are present early in the

pathogenesis of atherosclerotic lesions and are believed to activate monocytes, endothelial cells, and smooth muscle cells

by secreting cytokines. Fatty streaks cause no disturbances in blood flow and are discovered incidentally at autopsy. All of

the other lesions described are seen in fully developed atheromatous plaques. The histologic features of such plaques

include a central core of lipid debris that can have cholesterol clefts and can be calcified. There is usually an overlying cap

of smooth muscle cells. Hemorrhage is a complication seen in advanced atherosclerosis. Foam cells, derived from smooth

muscle cells or macrophages that have ingested lipid, can be present in all phases of atherogenesis.

22

A 59-year-old man has experienced chest pain at rest for the past year. On physical examination, his pulse is 80/min

and irregular. The figure shows the microscopic appearance representative of the patient's left anterior descending artery.

Which of the following laboratory findings is most likely to have a causal relationship to the process illustrated?

□ (A) Low Lp(a)

□ (B) Positive VDRL

Robbins & Cotran Review of Pathology Pg. 203

□ (C) Low HDL cholesterol

□ (D) Elevated platelet count

□ (E) Low plasma homocysteine

(C) The figure shows an arterial lumen that is markedly narrowed by atheromatous plaque complicated by calcification.

Hypercholesterolemia with elevated LDL and decreased HDL levels is a key risk factor for atherogenesis. Levels of Lp(a)

and homocysteine, if elevated, increase the risk of atherosclerosis. Syphilis (positive VDRL test result) produces

endarteritis obliterans of the aortic vasa vasorum, which weakens the wall and predisposes to aneurysms. Although

platelets participate in forming atheromatous plaques, their number is not of major importance. Thrombocytosis can result

in thrombosis or hemorrhage

23

After falling down a flight of stairs, a 59-year-old woman experiences mild intermittent right hip pain. Physical

examination shows a 3-cm contusion over the right hip. The area is tender to palpation, but she has full range of motion of

the right leg. A radiograph of the pelvis and right upper leg shows no fractures, but does show calcified, medium-sized

arterial branches in the pelvis. This radiographic finding is most likely to represent which of the following?

□ (A) Long-standing diabetes mellitus

□ (B) Benign essential hypertension

□ (C) An incidental observation

□ (D) Increased risk for gangrenous necrosis

□ (E) Unsuspected hyperparathyroidism

(C) Older adults with calcified arteries often have Mönckeberg medial calcific sclerosis, a benign process that is a form

of arteriosclerosis with no serious sequelae. Such arterial calcification is far less likely to be a consequence of

atherosclerosis with diabetes mellitus or with hypercalcemia. Hypertension is most likely to affect small renal arteries, and

calcification is not a major feature, although hypertension also is a risk factor for atherosclerosis

24

For more than a decade, a 45-year-old man has had poorly controlled hypertension ranging from 150/90 mm Hg to

160/95 mm Hg. Over the past 3 months, his blood pressure has increased to 250/125 mm Hg. On physical examination,

his temperature is 36.9°C. His lungs are clear on auscultation, and his heart rate is regular. There is no abdominal pain on

palpation. A chest radiograph shows a prominent border on the left side of the heart. Laboratory studies show that his

serum creatinine level has increased during this time from 1.7 mg/dL to 3.8 mg/dL. Which of the following vascular lesions

is most likely to be found in this patient's kidneys?

□ (A) Hyperplastic arteriolosclerosis

□ (B) Granulomatous arteritis

□ (C) Fibromuscular dysplasia

□ (D) Polyarteritis nodosa

□ (E) Hyaline arteriolosclerosis

(A) This patient has malignant hypertension superimposed on benign essential hypertension. Malignant hypertension

can suddenly complicate less severe hypertension. The arterioles undergo concentric thickening and luminal narrowing. A

granulomatous arteritis is most characteristic of Wegener granulomatosis, which often involves the kidney. Fibromuscular

dysplasia can involve the main renal arteries, with medial hyperplasia producing focal arterial obstruction. This process

can lead to hypertension, but not typically malignant hypertension. Polyarteritis nodosa produces a vasculitis that can

involve the kidney. Hyaline arteriolosclerosis is seen with long-standing essential hypertension of moderate severity.

These lesions give rise to benign nephrosclerosis. The affected kidneys become symmetrically shrunken and granular

because of progressive loss of renal parenchyma and consequent fine scarring

25

After a mastectomy with axillary node dissection for breast cancer 1 year ago, a 47-year-old woman has developed

persistent swelling and puffiness in the left arm. Physical examination shows firm skin over the left arm and “doughy”

underlying soft tissue. The arm is not painful or discolored. She developed cellulitis in the left arm 3 months ago. Which of

the following terms best describes these findings?

□ (A) Thrombophlebitis

□ (B) Subclavian arterial thrombosis

□ (C) Tumor embolization

□ (D) Lymphedema

□ (E) Vasculitis

(D) A mastectomy with axillary lymph node dissection leads to disruption and obstruction of lymphatics in the axilla.

Such obstruction to lymph flow gives rise to lymphedema, a condition that can be complicated by cellulitis.

Thrombophlebitis from venous stasis is a complication seen more commonly in the lower extremities. An arterial

thrombosis can lead to a cold, blue, painful extremity. Tumor emboli are generally small but uncommon. Vasculitis is not a

surgical complication

26

A study is conducted to investigate the pathogenesis of atherosclerosis. The investigators have developed genetically

modified mice that have hypercholesterolemia and spontaneously develop atherosclerosis. Next, the investigators

selectively delete individual genes to determine the factors that are crucial to the development of atherosclerosis. Deletion

of the gene encoding for which of the following is most likely to reduce the experimentally observed atherosclerosis in

these modified mice?

□ (A) Von Willebrand factor

□ (B) Homocysteine

□ (C) T-cell receptor

□ (D) Endothelin

□ (E) Fibrillin

□ (F) LDL receptor

□ (G) Factor VIII

□ (H) Apolipoprotein

(C) Deletion of T-cell receptor genes prevents T-cell development (because engagement of T-cell receptors during

development in the thymus is essential for T cell survival). Early in the course of atheroma formation, the T cells adhere to VCAM-1 on activated endothelial cells and migrate into the vessel wall. These T cells, activated by some unknown

mechanism, secrete various proinflammatory molecules that recruit and activate monocytes and smooth muscle cells and

perpetuate chronic inflammation of the vessel wall. The loss of T cells reduces atherosclerosis. Von Willebrand factor is

required for normal platelet adhesion to collagen, and its absence leads to abnormal bleeding. Homocysteine can damage

endothelium, and its absence may protect against atherosclerosis, but there is no evidence that homocysteine is the major

factor in initiating endothelial damage. That role, most likely, belongs to cholesterol. Endothelin is a vasoconstrictor with no

known role in atherogenesis. Fibrillin loss causes weakness of the arterial media, with risk for dissection, as seen in

Marfan syndrome. A reduction in LDL receptors or decreased apolipoprotein promotes atherogenesis in familial

hypercholesterolemia. Decreased factor VIII leads to abnormal bleeding.

27

An 80-year-old man with a lengthy history of smoking survived a small myocardial infarction several years ago. He now

reports chest and leg pain during exercise. On physical examination, his vital signs are temperature, 36.9°C; pulse, 81/min;

respirations, 15/min; and blood pressure, 165/100 mm Hg. Peripheral pulses are poor in the lower extremities. There is a

7-cm pulsating mass in the midline of the lower abdomen. Laboratory studies include two fasting serum glucose

measurements of 170 mg/dL and 200 mg/dL. Which of the following vascular lesions is most likely to be present in this

patient?

□ (A) Aortic dissection

□ (B) Arteriovenous fistula

□ (C) Atherosclerotic aneurysm

□ (D) Glomus tumor

□ (E) Polyarteritis nodosa

□ (F) Takayasu arteritis

□ (G) Thromboangiitis obliterans

(C) Abdominal aneurysms are most often related to underlying atherosclerosis. This patient has multiple risk factors for

atherosclerosis, including diabetes mellitus, hypertension, and smoking. When the aneurysm reaches this size, there is a

significant risk of rupture. An aortic dissection is typically a sudden, life-threatening event with dissection of blood out of

the aortic lumen, typically into the chest, without a pulsatile mass. The risk factors for atherosclerosis and hypertension

underlie aortic dissection. An arteriovenous fistula can produce an audible bruit on auscultation. Glomus tumors are

usually small peripheral masses. Polyarteritis nodosa can produce small microaneurysms in small arteries. Takayasu

arteritis typically involves the aortic arch and branches in children. Thromboangiitis obliterans (Buerger disease) is a rare

condition with occlusion of the muscular arteries of the lower extremities in smokers

28

A 61-year-old man has smoked two packs of cigarettes per day for the past 40 years. He has experienced increasing

dyspnea for the past 6 years. On physical examination, his vital signs are temperature, 37.1°C; pulse, 60/min; respirations,

18/min and labored; and blood pressure, 130/80 mm Hg. On auscultation, expiratory wheezes are heard over the chest

bilaterally. His heart rate is regular. A chest radiograph shows increased lung volume, with flattening of the diaphragms,

greater lucency to all lung fields, prominence of pulmonary arteries, and a prominent border on the right side of the heart.

Laboratory studies include blood gas measurements of Po2 of 80 mm Hg, Pco2 of 50 mm Hg, and pH of 7.35. He dies of

pneumonia. At autopsy, the pulmonary arteries have atheromatous plaques. Which of the following is most likely to have

caused these findings?

□ (A) Chronic renal failure

□ (B) Coronary atherosclerosis

□ (C) Cystic fibrosis

□ (D) Diabetes mellitus

□ (E) Familial hypercholesterolemia

□ (F) Obesity

□ (G) Phlebothrombosis

□ (H) Pulmonary emphysema

(H) The pulmonary vasculature is under much lower pressure than the systemic arterial circulation and is much less

likely to have endothelial damage, which promotes atherogenesis. Atherosclerosis in systemic arteries is more likely to

occur where blood flow is more turbulent, a situation that occurs at arterial branch points, such as in the first few

centimeters of the coronary arteries or in the abdominal aorta. Factors driving systemic arterial atherosclerosis (e.g.,

hyperlipidemias, smoking, diabetes mellitus, and systemic hypertension) do not operate in the pulmonary arterial

vasculature. Pulmonary hypertension, the driving force behind pulmonary atherosclerosis, occurs when pulmonary

vascular resistance increases as the pulmonary vascular bed is decreased by either obstructive (e.g., emphysema, as in

this patient) or restrictive (e.g., as in scleroderma with pulmonary interstitial fibrosis) diseases. Cystic fibrosis leads to

widespread bronchiectasis, not emphysema, but cystic fibrosis is still an obstructive lung disease with the potential to

produce pulmonary hypertension. Obesity leads to pulmonary hypoventilation, which acts as a restrictive lung disease, but

pulmonary hypoventilation does not increase lung volumes, as in this patient. Phlebothrombosis affects veins and leads to

possible pulmonary thromboembolism, which increases pulmonary pressures, but more acutely than in this patient.

29

A 75-year-old man has experienced headaches for the past 2 months. On physical examination, his vital signs are

temperature, 36.8°C; pulse, 68/min; respirations, 15/min; and blood pressure, 130/85 mm Hg. His right temporal artery is

prominent, palpable, and painful to the touch. His heart rate is regular, and there are no murmurs. A temporal artery biopsy

is performed, and the segment of temporal artery excised is grossly thickened and shows focal microscopic granulomatous

inflammation. He responds well to corticosteroid therapy. Which of the following complications of this disease is most likely to occur in untreated patients?

□ (A) Renal failure

□ (B) Hemoptysis

□ (C) Malignant hypertension

□ (D) Blindness

□ (E) Gangrene of the toes

(D) This patient has clinical features suggesting giant-cell (temporal) arteritis. This form of arteritis typically involves

large to medium-sized arteries in the head (especially temporal arteries), but also vertebral and ophthalmic arteries.

Involvement of the latter can lead to blindness. Because involvement of the kidney, lung, and peripheral arteries of the

extremities is much less common, renal failure, hemoptysis, and gangrene of toes are unusual. There is no association

between hypertension and giant-cell arteritis.

30

A 30-year-old woman has smoked one pack of cigarettes per day since she was a teenager. She has had painful

thromboses of the superficial veins of the lower legs for 1 month and episodes during which her fingers become blue and

cold. Over the next year, she develops chronic, poorly healing ulcerations of her feet. One toe becomes gangrenous and

is amputated. Histologically, at the resection margin, there is an acute and chronic vasculitis involving medium-sized

arteries, with segmental involvement. Which of the following is the most appropriate next step in treating this patient?

□ (A) Hemodialysis

□ (B) Smoking cessation

□ (C) Corticosteroid therapy

□ (D) Antibiotic therapy for syphilis

□ (E) Insulin therapy

(B) This patient has features of thromboangiitis obliterans (Buerger disease). This disease, which affects small to

medium-sized arteries of the extremities, is strongly associated with smoking. Renal involvement does not occur.

Immunosuppressive therapy is not highly effective. Syphilis produces an aortitis. Although peripheral vascular disease with

atherosclerosis is a typical finding in diabetes mellitus, vasculitis is not.