19 - Pathology of Pulmonary Vascular Disease

Question 1

What causes pulmonary edema?

Answer 1

Imbalanced Starling forces (hydrostatic and oncotic pressures)

Question 2

What are the gross and histological pathological findings of pulmonary edema?

Answer 2

Gross
- lungs are heavy and wet

Histological

• congested alveolar capillaries
• some blood in alveoli (hemosiderin laden macrophages)
• pink edema fluid in alveoli

Question 3

What are the three histological phases of acute respiratory syndrome?

Answer 3

Acute phase = exudative

• edema
• hemorrhage
• hyaline membranes

Subacute = fibroproliferative
- fibroblasts in interstitium and alveoli

Chronic = fibrotic

• type II cells proliferate
• fibrosis with architectural distortion
• cysts
• lots of very pink collagen
• not many cells

Question 4

What does diffuse alveolar damage suggest?

Answer 4

acute respiratory distress syndrome or acute interstitial pneumonia

Question 5

What distinguishes between acute respiratory distress syndrome and acute interstitial pneumonia? What are the similarities between the two diseases?

Answer 5

ARDS has a known inciting event; AIP does not have a known inciting event

Similarities

• high mortality
• diffuse alveolar damage

Question 6

What are the gross and histological appearances of a pulmonary infarction?

Answer 6

Gross - red, wedge shaped zone

Histological

• coagulation necrosis
• alveolar ghosts (nuclei gone)
• architecture preserved
• extravasation of RBCs into airspaces

Question 7

What are the many types of emboli?

Answer 7

• thrombotic
• fat / bone marrow
• amniotic fluid
• foreign material (often with multinucleated giant cells in vessel wall)
• air
• tumor
• parasites

Question 8

What does a foreign material emboli with multinucleated giant cells in the vessel wall suggest?

Answer 8

Intravenous drug use

Question 9

What is the clinical manifestation of a fat embolis?

Answer 9

• hypoxemia
• CNS dysfunction
• petechiae rash
• free fatty acids may have a toxic effect

Question 10

What happens to a persistent pulmonary embolism?

Answer 10

may be incorporated into the vessel wall (organization); can lead to chronic thromoembolic disease

Question 11

What happens to pulmonary arterioles in pulmonary hypertension?

Answer 11

They develop a muscular layer (become muscularized)

Question 12

What is the histologic appearance of pulmonary venous hypertension?

Answer 12

• small lumen
• muscularization of arterioles
• muscular arteries with thickening of media and intima
• elastic arteries with atheromata

Question 13

What is the histologic appearance of pulmonary arterial hypertension?

Answer 13

• hypertrophy of media
• intimal thickening
• muscularization of arterioles
• in-situ thrombosis
• angiomatoid lesions
• plexiform lesions (severe disease)
• necrotising arteritis (very severe disease)