Lecture 21: Pathology of Vascular Disease Flashcards
PE: risk factors
Hypercoagulability, carcinoma/Trousseau’s syndrome, protein C/S deficiency, oral contraceptives, pregnancy
PE: gross (massive embolism)
Massive embolism may show no parenychymal changes because death happened very quickly
PE: gross (smaller embolism)
Wedge shaped, hemorrhagic parenchyma (due to dual blood supply), will organize (fibrous) and eventually scar
What finding is indicative of a true embolism and not a postmortem clot?
Lines of Zahn
How does the hemorrhagic infarct form?
Because bronchial arteries don’t supply alveoli and pulmonary artery blocked, alveoli will undergo necrosis up to bronchial blood supply, and then blood will be pumped into this space
What happens to infarction following PE?
Hemorrhagic area becomes subpleural scaring (triangle shaped, retracted)
Define pulmonary hypertension; what % of systemic pressure to reach hypertensive level?
Hemodynamic consequence of various conditions that lead to chronic elevation of PA pressure; at least 25% of systemic pressure (normal is 10%)
What finding in pulmonary arteries suggests pulmonary hypertension?
Pulmonary atherosclerosis
Pulmonary hypertension: primary and secondary
Primary = due to intrinsic abnormality of vessels; Secondary = due to something other than vessels
When you think of primary hypertension, think of __________ lesions
Plexiform
Is primary pulmonary HTN common? Who gets it? Etiology?
No: rare; young women; idiopathic or due to collagen vascular disease, drugs (diet drug, phenphen)
What are some etiologies of secondary pulmonary HTN?
Heart disease (malformation, CHF) or severe lung disease (COPD, fibrosis)
What is a consequence of recurrent thromboembolism?
Pulmonary HTN!
How does primary pulmonary HTN present? Survival?
Progressive SOB, syncope, maybe sudden death; 5 years = 35%
Grading of pulmonary hypertension: Which grade is no longer reversible?
Grade III: subintimal fibrosis with onion-ring appearance; marked reduplication of internal elastic membrane; arteries and arterioles resemble pipes (concentric fibrosis)
Grading of pulmonary hypertension: Which grade is associated with plexiform lesions?
Grade IV to V
Describe a plexiform lesion
Herniation of vessel wall –> dilated segment taking vessel wall with it and contains numerous slits like vascular channels
What finding do you get with chronic thromboembolic disease? What do they look like?
Organized thrombus within arterial wall; they demonstrate recanalization
Vasculitic disorders affect the lung: 3 more common ones
Granulomatosis with polyangiitis (Wegener’s granulomatosis); Churg-Strauss disease (eosinophilic granulomatosis with polyangiitis); Microscopic polyangiitis
Describe GPA/Wegener’s: who gets it and the triad; what do you get in the lung?
Wide age range, mean is 50; Triad: sinus, lung, and renal involvement; multiple lung nodules
What is positive in most cases of GPA/Wegener’s
C-ANCA (anti-proteinase 3)
GPA/Wegener’s: histology
IRREGULAR, parenchymal necrosis w/ neutrophils surrounded by scattered giant cells/histiocytes
Why don’t you get well-formed granulomas in GPA/Wegener
Necrosis FIRST due to autoimmune disorder with giant cells reacting SECOND (unlike reaction to an antigen FIRST)
GPA/Wegener: vasculitis component
Medium sized arteries/veins –> capillaries
GPA/Wegener: earliest manifestation
Palisaded microgranulomas
Churg-Strauss: triad
Asthma, eosinophilia, vasculitis
What separates Churg-Strauss from Wegener’s
Neuropathy and cardiac involvement (but NOT renal); EOSINOPHILIC disease
Churg-Strauss: radiograph
Multifocal infiltrates that may change over time
Churg-Strauss: histology
Histology – asthmatic bronchitis, eosinophilic pneumonia, STELLATE GRANULOMAS and vasculitis
Churg-Strauss: granulomas
Palisaded histiocytes and multinucleated giant cells, surrounding a central necrotic zone replete with eosinophils
Microscopic polyangiitis “ANCA”
P-ANCA
Microscopic polyangiitis (MPA): describe
Immune vasculitis restricted to arterioles, venules, and capillaries with common kidney involvement
MPA on biopsy: what you see what what you don’t
Diffuse alveolar hemorrhage with neutrophilic capillaritis; No granulomas, giant cells, eosinophilia
MPA: where do you find neutrophils?
Within septa (not in the airspaces themselves)
When someone has ongoing (> a day or so) hemorrhage in the alveoli, what happens next?
Hemosiderin deposition in the tissue and within the macrophages
Diffuse alveolar hemorrhage: common? dangerous? clinical symptom? typical association?
Rare but life-threatening (respiratory failure), you will see hemoptysis; typically associated with microscopic polyangiitis
