Vascular Pathology — MCQs

A study is conducted involving persons with LDL cholesterol levels above 160 mg/dL. These individuals have increased oxidized LDL deposited in their arteries, leading to decreased arterial lumen size, particularly at branch points. Which of the following is the most likely initial pathologic change in these areas of arterial narrowing?

Q105Medium

Hyperplastic arteriolitis with necrotizing arteriolitis is seen in?

Q106Easy

Both pale and hemorrhagic infarcts are found in which organ?

Q107Easy

Which of the following cells does not participate in atherogenesis?

Q108Medium

Most arterial emboli originate from which one of the following sites?

Q109Medium

Digital gangrene is most likely seen in which condition?

Q110Easy

Caisson's disease is a type of:

Vascular Pathology Indian Medical PG Practice Questions and MCQs

Question 101: What are the common pathological changes seen in the kidney in benign hypertension?

A. Fibronoid necrosis
B. Microaneurysm
C. Hyaline arteriosclerosis (Correct Answer)
D. Thinning of walls

Explanation: **Explanation:** In **benign hypertension**, the kidney undergoes characteristic structural changes known as **Benign Nephrosclerosis** [1]. The hallmark pathological finding is **Hyaline Arteriosclerosis** [2]. **1. Why Hyaline Arteriosclerosis is correct:** Chronic hemodynamic stress (high blood pressure) causes plasma proteins to leak across the injured vascular endothelium into the vessel wall. This is accompanied by increased smooth muscle cell matrix synthesis [1]. Microscopically, this appears as a **homogeneous, pink, glassy (hyaline) thickening** of the walls of arterioles, leading to luminal narrowing and downstream ischemic atrophy [1], [2]. **2. Analysis of Incorrect Options:** * **A. Fibrinoid Necrosis:** This is the hallmark of **Malignant Hypertension** (Accelerated Hypertension). It involves acute vascular injury with the deposition of fibrin-like material and inflammation within the vessel wall, often associated with "onion-skin" hyperplastic arteriolosclerosis [2]. * **B. Microaneurysm:** While associated with hypertension, Charcot-Bouchard microaneurysms are typically found in the **brain** (basal ganglia), not the kidney. In the kidney, hypertension usually causes narrowing, not aneurysmal dilation. * **C. Thinning of walls:** Hypertension leads to **thickening** of the vessel walls (hypertrophy and hyalinization) to withstand pressure, not thinning [1]. **3. NEET-PG High-Yield Pearls:** * **Gross Appearance:** The kidney in benign hypertension shows a **"Grainy Leather"** appearance (symmetrical contraction with fine surface granularity) [1]. * **Malignant Hypertension:** Look for **"Flea-bitten kidney"** (pinpoint petechial hemorrhages) and **Hyperplastic Arteriolosclerosis** (onion-skinning) [2]. * **Key Distinction:** Benign = Hyaline Arteriosclerosis; Malignant = Fibrinoid Necrosis + Hyperplastic Arteriosclerosis [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, pp. 943-945. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 498-499.

Question 102: Ascending aorta involvement is the commonest site of which type of aneurysm?

A. Syphilitic (Correct Answer)
B. Atherosclerotic
C. Mycotic
D. None of the above

Explanation: The **ascending aorta** is the classic and most common site for **Syphilitic (Luetic) aneurysms** [1]. This occurs during the tertiary stage of syphilis due to *Treponema pallidum* invading the **vasa vorum** of the aortic arch [1]. This leads to obliterative endarteritis, resulting in ischemia of the tunica media, loss of elastic fibers, and subsequent weakening of the vessel wall. Grossly, this presents as a **"tree-bark" appearance** of the intimal surface. **Analysis of Options:** * **Atherosclerotic Aneurysms:** These are the most common type of aortic aneurysms overall, but they characteristically involve the **abdominal aorta** (specifically the infrarenal segment) [2]. Atherosclerosis rarely involves the ascending aorta primarily. * **Mycotic Aneurysms:** These are caused by bacterial or fungal infections of the arterial wall (often secondary to infective endocarditis) [2]. While they can occur anywhere, they most commonly affect the **femoral artery, cerebral arteries (causing subarachnoid hemorrhage), or the abdominal aorta**, rather than specifically targeting the ascending segment. **High-Yield Clinical Pearls for NEET-PG:** * **Tree-barking:** A pathognomonic gross finding in syphilitic aortitis due to scarring. * **Complications:** Syphilitic aneurysms often lead to **aortic regurgitation** (due to dilation of the aortic ring) and narrowing of the coronary ostia [1], leading to angina [3]. * **DeBakey Classification:** Remember that Type I and II aortic dissections involve the ascending aorta, but these are distinct from the chronic aneurysmal changes seen in syphilis. * **Most common site for any aneurysm:** Abdominal Aorta (Atherosclerotic) [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Infectious Diseases, pp. 388-389. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 510-511. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 511-512.

Question 103: In benign hypertension, what is the commonest vascular pathology?

A. Atherosclerosis
B. Fatty infiltration of intima
C. Fibrinoid necrosis
D. Hyaline arteriosclerosis (Correct Answer)

Explanation: **Explanation:** The hallmark vascular change in **benign hypertension** is **Hyaline Arteriosclerosis** [1]. This occurs due to two primary mechanisms: the leakage of plasma proteins across injured endothelial cells into the vessel wall and increased synthesis of extracellular matrix by smooth muscle cells in response to chronic hemodynamic stress [2]. On histology, this appears as a homogenous, pink, "glassy" thickening of the arteriolar walls with narrowing of the lumen, leading to downstream ischemia (e.g., benign nephrosclerosis) [1], [3]. **Analysis of Incorrect Options:** * **Atherosclerosis:** This involves large and medium-sized elastic and muscular arteries (like the aorta or coronary arteries) and is characterized by intimal plaques (atheromas), not the generalized arteriolar thickening seen in hypertension. * **Fatty infiltration of intima:** This is an early stage of atherosclerosis (fatty streaks) rather than a primary hypertensive change. * **Fibrinoid necrosis:** This is the characteristic lesion of **malignant hypertension** (accelerated phase) [2], [4]. It involves acute vessel wall damage with fibrin deposition and "smudgy" eosinophilic appearance, often accompanied by "onion-skin" hyperplastic arteriolitis [4]. **High-Yield NEET-PG Pearls:** * **Benign Hypertension:** Hyaline Arteriosclerosis (Commonest in kidneys; also seen in elderly and diabetics) [1]. * **Malignant Hypertension:** Fibrinoid Necrosis + Hyperplastic Arteriolitis (Onion-skinning) [4]. * **Key Site:** The afferent arterioles of the kidney are most frequently involved in hypertensive changes [4]. * **Consequence:** Hyaline change in the kidneys leads to **Benign Nephrosclerosis**, characterized by symmetrically shrunken kidneys with a finely granular "grain-leather" surface [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, pp. 943-945. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 498-499. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Diseases Of The Urinary And Male Genital Tracts, pp. 541-542. [4] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, p. 945.

Question 104: A study is conducted involving persons with LDL cholesterol levels above 160 mg/dL. These individuals have increased oxidized LDL deposited in their arteries, leading to decreased arterial lumen size, particularly at branch points. Which of the following is the most likely initial pathologic change in these areas of arterial narrowing?

A. Endothelial cell disruption
B. Intimal thickening (Correct Answer)
C. Lymphocytic infiltrates
D. Platelet aggregation

Explanation: The question describes the pathogenesis of **Atherosclerosis**, a chronic inflammatory response of the arterial wall to endothelial injury. **1. Why Intimal Thickening is Correct:** The "Response to Injury" hypothesis states that atherosclerosis begins with **endothelial dysfunction** (not necessarily disruption) [4]. This dysfunction leads to increased permeability, leukocyte adhesion, and the accumulation of oxidized LDL in the intima [2]. The hallmark **initial pathologic change** in the vessel wall is the migration of smooth muscle cells from the media into the intima, where they proliferate and deposit extracellular matrix [1]. This process, known as **intimal thickening**, is the stereotypical response of the arterial wall to any insult and represents the precursor to a mature fibrofatty plaque [1], [3]. **2. Why Incorrect Options are Wrong:** * **A. Endothelial cell disruption:** While endothelial *dysfunction* (biochemical/functional change) is the trigger, physical *disruption* (denudation) is generally not seen in the early stages of atherosclerosis [4]. The endothelium remains structurally intact but "leaky." * **C. Lymphocytic infiltrates:** While T-cells are present in atherosclerotic lesions, they are part of the chronic inflammatory progression rather than the initial structural change. The primary early cellular event involves macrophages and smooth muscle cells [2]. * **D. Platelet aggregation:** This is typically a late-stage complication occurring after plaque rupture or erosion, leading to acute thrombosis. It is not the initial pathologic change of narrowing. **Clinical Pearls for NEET-PG:** * **Earliest visible lesion:** Fatty streak (macrophage foam cells in the intima) [2]. * **Most common site:** Abdominal aorta > Coronary arteries > Popliteal arteries > Internal carotid. * **Key Cytokines:** PDGF (Platelet-derived growth factor) and TGF-α are responsible for smooth muscle cell migration and intimal thickening [1]. * **Branch points:** Atherosclerosis preferentially occurs at branch points and ostia due to **disturbed/turbulent blood flow**, which induces pro-inflammatory gene expression in endothelial cells [4]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 494-495. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 505-506. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 504-505. [4] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 502-503.

Question 105: Hyperplastic arteriolitis with necrotizing arteriolitis is seen in?

A. Buerger's disease
B. Benign hypertension
C. Malignant hypertension (Correct Answer)
D. Diabetes

Explanation: **Explanation:** The hallmark of **Malignant Hypertension** (systolic >200 mmHg, diastolic >120 mmHg) is severe, acute vascular injury [2]. This manifests histologically as two distinct patterns: 1. **Hyperplastic Arteriolitis:** Characterized by "onion-skin" thickening of the vessel wall due to concentric proliferation of smooth muscle cells and duplicated basement membranes [1]. This is a physiological response to contain high intraluminal pressure. 2. **Necrotizing Arteriolitis:** Occurs when the extreme pressure causes fibrinoid necrosis (deposition of plasma proteins/fibrin) and inflammation within the vessel wall, often seen in the kidneys [2]. **Why other options are incorrect:** * **Buerger’s Disease (Thromboangiitis obliterans):** This is a segmental, thrombosing vasculitis of small/medium arteries (typically in smokers). It features microabscesses within thrombi, not hyperplastic changes. * **Benign Hypertension:** This is associated with **Hyaline Arteriolosclerosis**, where chronic, low-grade pressure causes plasma protein leakage, resulting in a homogenous, pink, glassy thickening of the wall without the "onion-skin" appearance [2]. * **Diabetes:** Primarily causes hyaline arteriolosclerosis (similar to benign hypertension) and non-enzymatic glycosylation of the basement membrane [2]. **High-Yield Clinical Pearls for NEET-PG:** * **Onion-skinning** = Malignant Hypertension [1]. * **Hyaline change** = Benign Hypertension or Diabetes [2]. * **Flea-bitten kidney:** Gross appearance in malignant hypertension due to petechial hemorrhages from necrotizing arteriolitis [1]. * **Mönckeberg Medial Sclerosis:** Calcification of the tunica media in elderly patients; it does *not* narrow the lumen. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Kidney, p. 945. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 498-499.

Question 106: Both pale and hemorrhagic infarcts are found in which organ?

A. Liver
B. Brain (Correct Answer)
C. Heart
D. Kidney

Explanation: **Explanation:** The nature of an infarct (pale vs. hemorrhagic) is primarily determined by the tissue's vascular supply and density. **Why Brain is the Correct Answer:** The brain is unique because it can exhibit both types of infarcts depending on the mechanism of injury. 1. **Pale (Anemic) Infarcts:** These typically occur due to **thrombotic arterial occlusion** [1]. Since the brain tissue is relatively solid (until liquefactive necrosis sets in), the lack of blood flow results in a pale area of necrosis. 2. **Hemorrhagic (Red) Infarcts:** These occur in the brain following **embolic occlusion** [1]. When an embolus lodges and then fragments or undergoes lysis (reperfusion), blood flows into the previously ischemic, necrotic tissue [1]. Because the brain has a loose texture, blood easily extravasates, turning a pale infarct into a hemorrhagic one. **Analysis of Incorrect Options:** * **Liver:** The liver has a **dual blood supply** (Portal vein and Hepatic artery). While this makes it resistant to infarction, when they do occur, they are typically **hemorrhagic**. * **Heart:** The heart is a solid organ with end-arterial circulation. Myocardial infarctions are almost exclusively **pale**. * **Kidney:** Like the heart, the kidney is a solid organ with a single arterial supply. Renal infarcts are the classic example of **pale, wedge-shaped infarcts**. **High-Yield NEET-PG Pearls:** * **Pale Infarcts:** Occur in solid organs with single venous drainage (Heart, Spleen, Kidney). * **Hemorrhagic Infarcts:** Occur in tissues with dual circulation (Lung, Liver), loose tissues (Bowel, Testis), or following reperfusion [1]. * **Liquefactive Necrosis:** The brain is the only organ where ischemic injury leads to liquefactive necrosis rather than coagulative necrosis [1]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1266-1269.

Question 107: Which of the following cells does not participate in atherogenesis?

A. Neutrophil (Correct Answer)
B. Platelet
C. Monocyte
D. Smooth muscle

Explanation: **Explanation:** Atherogenesis is a chronic inflammatory response of the arterial wall to endothelial injury [4]. The "Response to Injury" hypothesis outlines the specific cellular players involved in this process. **Why Neutrophils are the correct answer:** While neutrophils are the hallmark of *acute* inflammation [1], they do not play a primary or structural role in the initiation and progression of the atherosclerotic plaque. Atherosclerosis is characterized by chronic inflammation and fibroproliferative changes, where macrophages and lymphocytes dominate rather than polymorphonuclear leukocytes (neutrophils) [3]. **Analysis of incorrect options:** * **Monocytes (Option C):** These are the most critical cells in early atherogenesis. They migrate into the subendothelial space, differentiate into **macrophages**, and ingest oxidized LDL to become **foam cells**, forming the "fatty streak" [2]. * **Smooth Muscle Cells (Option D):** In response to growth factors (like PDGF), SMCs migrate from the media to the intima. They proliferate and synthesize extracellular matrix (collagen), which stabilizes the plaque by forming the **fibrous cap** [2]. * **Platelets (Option B):** Platelets adhere to injured endothelium or exposed collagen. They release growth factors (PDGF, TGF-β) that trigger smooth muscle cell migration and proliferation [4]. **NEET-PG High-Yield Pearls:** * **Initial event:** Endothelial injury/dysfunction [4]. * **Earliest visible lesion:** Fatty streak (can be seen in infants) [2]. * **Key Growth Factor:** **PDGF** (Platelet-Derived Growth Factor) is primarily responsible for smooth muscle cell migration. * **Major Cytokine:** **IFN-gamma** (secreted by T-cells) inhibits collagen synthesis, potentially leading to unstable plaques. * **Location:** Most common site is the **Abdominal Aorta**, followed by Coronary arteries [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Inflammation and Repair, p. 89. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 505-506. [3] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 200-202. [4] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 502-503.

Question 108: Most arterial emboli originate from which one of the following sites?

A. Cardiac valve
B. Left atrium (Correct Answer)
C. Left ventricle
D. Thoracic aorta

Explanation: **Explanation:** Systemic arterial emboli refer to emboli traveling within the arterial circulation, 80% of which originate from **intracardiac mural thrombi** [2]. **Why Left Atrium is the correct answer:** While both the left atrium and ventricle are major sources, the **left atrium** (specifically the left atrial appendage) is the most frequent site of thrombus formation leading to systemic embolization [1]. This is primarily due to the high prevalence of **Atrial Fibrillation (AF)** and mitral valve disease, which cause blood stasis and subsequent thrombus formation [3]. In the context of NEET-PG, unless a specific condition like a recent Myocardial Infarction (MI) is mentioned, the left atrium remains the statistically dominant source. **Analysis of Incorrect Options:** * **Cardiac Valve (A):** While vegetations from Infective Endocarditis can embolize, they represent a smaller percentage of total systemic emboli compared to mural thrombi. * **Left Ventricle (C):** This is the second most common site. Thrombi here usually follow a recent MI (due to dyskinetic wall motion) or dilated cardiomyopathy [2]. However, AF-related atrial thrombi are more frequent in the general population. * **Thoracic Aorta (D):** Ulcerated atherosclerotic plaques in the aorta can lead to cholesterol emboli, but this is significantly less common than cardiac sources. **High-Yield Clinical Pearls for NEET-PG:** * **Most common site of lodgment:** The **Lower Extremities** (75%), followed by the brain (via carotid arteries) [1]. * **Paradoxical Embolism:** An embolus originating in the venous circulation that enters the systemic arterial circulation via a Right-to-Left shunt (e.g., Patent Foramen Ovale or ASD). * **Virchow’s Triad:** Stasis, endothelial injury, and hypercoagulability are the prerequisites for any thrombus formation [2]. **References:** [1] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 145-146. [2] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Hemodynamic Disorders, Thromboembolic Disease, and Shock, pp. 136-137. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. The Central Nervous System, pp. 1266-1268.

Question 109: Digital gangrene is most likely seen in which condition?

A. Takayasu arteritis
B. Kawasaki disease
C. Polyarteritis nodosa (Correct Answer)
D. Wegener's granulomatosis

Explanation: **Polyarteritis Nodosa (PAN)** is a systemic necrotizing vasculitis that primarily affects small-to-medium-sized muscular arteries. The hallmark of PAN is segmental, transmural inflammation that leads to fibrinoid necrosis and weakening of the arterial wall [1]. This process results in luminal narrowing, thrombosis, and ischemia of the supplied tissues [1]. Because PAN frequently involves the distal arteries of the extremities (like the digital arteries) while **sparing the capillaries and venules**, it commonly presents with **digital gangrene**, skin ulcers, and livedo reticularis. **Why other options are incorrect:** * **Takayasu Arteritis:** A large-vessel vasculitis (Granulomatous) primarily affecting the aorta and its main branches. It typically presents with "pulseless disease," limb claudication, or renovascular hypertension, rather than distal digital gangrene. * **Kawasaki Disease:** A medium-vessel vasculitis seen in children. While it involves coronary arteries (leading to aneurysms), its peripheral manifestations are usually erythema and desquamation of the hands and feet, not frank gangrene. * **Wegener’s Granulomatosis (GPA):** A small-vessel vasculitis characterized by the triad of upper respiratory tract, lower respiratory tract, and renal involvement (pauci-immune glomerulonephritis) [3]. While skin lesions occur, digital gangrene is far more characteristic of PAN. **High-Yield Clinical Pearls for NEET-PG:** * **Association:** PAN is strongly associated with **Hepatitis B surface antigen (HBsAg)** in about 30% of cases [2]. * **Key Feature:** PAN characteristically **spares the lungs** (pulmonary arteries are not involved). * **Imaging:** Angiography often shows a **"string of pearls"** appearance due to multiple aneurysms and constrictions [1]. * **Marker:** PAN is typically **ANCA-negative**, distinguishing it from Microscopic Polyangiitis (MPA) [2]. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 517-518. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Osteoarticular And Connective Tissue Disease, pp. 687-688. [3] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Diseases of Infancy and Childhood, pp. 519-520.

Question 110: Caisson's disease is a type of:

A. Gas embolism (Correct Answer)
B. Fat embolism
C. Amniotic fluid embolism
D. Tumor embolism

Explanation: **Explanation:** **Correct Answer: A. Gas embolism** **Caisson’s disease** (also known as decompression sickness) is a chronic form of gas embolism [1], [2]. It occurs in individuals exposed to sudden changes in atmospheric pressure, such as deep-sea divers or underwater construction workers. * **Mechanism:** When a person breathes air at high pressure (deep underwater), increased amounts of nitrogen gas dissolve in the blood and tissues [2]. If the person ascends (decompresses) too rapidly, the nitrogen cannot stay dissolved and forms **gas bubbles** in the blood and tissues [1]. * **Clinical Features:** These bubbles cause "the bends" (joint/muscle pain) and "the chokes" (respiratory distress) [1]. The chronic form, Caisson’s disease, is characterized by **ischemic necrosis** of bones (femur, tibia, and humerus) [1]. **Why other options are incorrect:** * **B. Fat Embolism:** This typically occurs after fractures of long bones or severe soft tissue trauma, where marrow fat globules enter the circulation. It is characterized by the triad of respiratory distress, neurological symptoms, and petechial rashes. * **C. Amniotic Fluid Embolism:** A catastrophic obstetric complication where amniotic fluid enters maternal circulation via placental tears, leading to DIC and shock [1]. * **D. Tumor Embolism:** Occurs when fragments of a malignant tumor enter the vasculature, often leading to distant metastasis. **High-Yield Clinical Pearls for NEET-PG:** * **Acute form:** Decompression sickness (Bends and Chokes). * **Chronic form:** Caisson’s disease (characterized by multifocal **Avascular Necrosis** of bone) [1]. * **Treatment:** Hyperbaric oxygen chambers (to force gas back into solution) [1]. * **Minimum air volume:** Approximately 100ml of air is required to cause a clinically significant/fatal air embolism in humans. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Hemodynamic Disorders, Thromboembolic Disease, and Shock, pp. 138-140. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. Common Clinical Problems From Respiratory Tract Disease, pp. 323-324.

Practice by Chapter

Atherosclerosis

Practice Questions

Hypertensive Vascular Disease

Practice Questions

Aneurysms and Dissection

Practice Questions

Vasculitis

Practice Questions

Venous Disease and Thrombosis

Practice Questions

Vascular Tumors

Practice Questions

Varicose Veins and Lymphatics

Practice Questions

Pathology of Vascular Interventions

Practice Questions

Vascular Diseases in Specific Organs

Practice Questions

Congenital Vascular Anomalies

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free