Respiratory System Pathology 3 - Galbraith Flashcards Preview

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Flashcards in Respiratory System Pathology 3 - Galbraith Deck (27):

Chronic diffuse interstitial lung diseases

Cause inflammation and fibrosis of the interstitial

Cause restrictive lung diseases. Interstitial fibrosis leads to:
-decreased diffusing capacity
-decreased lung volume
-decreased lung compliance

Advanced stages - difficult to differentiate due to extensive scarring - honeycomb lung

Categorized by:


Idiopathic pulmonary fibrosis

progressive interstitial fibrosis and respiratory failure

Unknown cause
Secondary to repeated injury to alveolar epithelial cells with a pro-fibrotic response in genetically susceptible people


Idiopathic pulmonary fibrosis incidence

older than 50

Injury due to:
tobacco smoke
occupational irritants - fumes, dusts
persistent GERD

Telomerase mutations - TERT, TERC
Surfactant mutations
MUC5B variant


Idiopathic pulmonary fibrosis morphology

Usual Interstitial Pneumonia (UIP)

Sub pleural and interlobular septal fibrosis

Fibrosis patchy, variable in intensity and age
-Early lesion show cellular fibroblastic foci

"Honeycomb fibrosis" with spaces surrounded by dense collagen, line with hyper plastic type II pneumocytes and bronchial epithelium


Idiopathic pulmonary fibrosis clinical course

gradual worsening dyspnea with exertion

Development of progressive hypoxemia, cyanosis, clubbing occurring late

Rate of deterioration is variable

Medial survival 3 yrs


Nonspecific interstitial pneumonia

Diffuse interstitial disease with a better prognosis than diseases featuring UIP

Two histologic patterns:
-Cellular (interstitial chronic inflammation)
-Fibrosing (interstitial fibrosis, lesions are the same stage of development)

Women, 50s, no smoking association

Dyspnea, cough


Cryptogenic organizing pneumonia (COP)

Tufts, balls or plugs of immature fibroblastic tissue (Masson bodies) found within terminal bronchioles, alveolar ducts, alveolar spaces

No interstitial fibrosis
Connective tissue plugs at same stage of development

Underlying lung architecture is normal

Arise in various infectious or inflammatory lung injuries
-present with cough, dyspnea
-resolve spontaneously or with steroid therapy



Exposure to mineral dusts, inorganic and organic particles, chemical fumes

Influenced by:
-partial size (1-5 um most pathogenic)
-Particle solubility
-Level and duration of exposure/effectiveness of clearance
-intensity of immune response


Coal worker's lung disease

inhaled carbon dust taken up by macrophages - accumulate in interstitial tissue along pulmonary lymphatic tissue

Anthracosis - black pigmented lesions formed by coal dust containing macrophages

Seen in smokers and urban dwellers

can cause centriacinar emphysema


Complicated coal worker's pneumoconiosis

Progressive massive fibrosis

Characterized by multiple anthracitic scars, when extensive lead to:
respiratory failure
pulmonary HTN
Cor pulmonale



Inhaling crystalline silicon dioxide over long periods of time

Crystalline particles ingested by macrophages, then mounts inflammatory response
-slowly growing nodular collagenous scars
-over time coalesce --> progressive massive fibrosis


Silicosis morphology

nodular scars in lungs or hilar LN
-calcified LN identified with CXR

Nodules: whorled balls of dense collagen fibers, surrounded by dust-containing macrophages
-more prominent apically

silica particles birefringent with plane-polarized light


Silicosis - clinical course

Rate of onset and disease progression variable
-progress after exposure ceases

Increased susceptibility to TB

2x risk of lung CA



fibrous hydrated silicate crystals

cause interstitial and pleural fibrosis --> lung carcinoma and malignant mesothelioma

Types: serpentine, amphibole


Asbestos-related lung disease

asbestos fibers taken by macrophages, causes inflammatory response leading to interstitial fibrosis

interstitial fibrosis pattern --> honeycomb lung

Lung bases affected FIRST and progresses upwards

characterized by asbestos (or ferruginous) bodies within macrophages

Plaques of dense collagen, sometimes calcified, form on pleura, particularly parietal pleura
-may result in pleural effusion

predisposed to malignancy, exacerbated by smoking


Asbestosis-related lung disease presentation

Present similar to pneumoconiosis or usual interstitial pneumonia (patchy areas of different ages)

symptoms appear decades after exposure

Pleural plaques asymptomatic

complicated by lung or pleural malignancy carries a poor prognosis



Multiorgan granulomatous disorder - unknown cause

Lung and/or hilar LN in 90% of cases

Dx of exclusion

arise from abnormal immune regulation


incidence and genetic component of Sarcoidosis

younger than 40
10X higher in African-Americans

Family/race clustering
HLA-A1 and HLA-B8


Sarcoidosis morphology

small, noncaseating granulomas with multinucleate giant cells - naked granulomas

Lungs commonly involved with granulomas distributed along pulmonary lymphatics
-granulomas may coalesce forming grossly-apparent nodules up to 2 cm in diameter

Other sites involved: Liver, spleen, bone marrow, skin, eye


Sarcoidosis clinical course

Constitutional symptoms: weight loss, fever, fatigue, night sweats

Pulmonary symptoms: dyspnea, hemoptysis, cough, pain

Resolution with or without steroids
-20% residual pulmonary impairment
10% develop progressive pulmonary fibrosis, PHTN, and cor pulmonale


Hypersensitivity pneumonitis

Immunologic reaction to inhaled organic antigens causing:
-interstitial pneumonitis - lymphocytes, plasma cells, macrophage
-noncaseating granulomas
-Interstitial fibrosis

Continued antigen exposure -->> progressive fibrotic lung disease


Antigens implicated in hypersensitivity pneumonitis

Thermophilic bacteria - air conditioner lung

antigens from bird excretions or feathers - bird fancier's disease

Various spore-forming fungi or bacteria - farmer's lung


Desquamative interstitial pneumonia

alveoli filled with numerous macrophages
-some with phagocytosed surfactant

Mild chronic inflammation and fibrosis


Persistent dry cough, dyspnea, clubbing

Responds to steroid therapy


Respiratory bronchiolitis - associated interstitial lung disease

peribronchiolar fibrosis and chronic inflammation

associated with anthracotic macrophages in bronchiolar lumens

incidental finding in many smokers

cough, dyspnea in long term smokers

treated with smoking cessation


Pulmonary Langerhans cell histiocytosis

Accumulation of Langerhans cells (dendritic cells) to form nodules, along with fibroblasts, macrophages, eosinophils

young smokers

lesions behave as reactive processes, others have shown BRAF mutations


Pulmonary alveolar proteinosis (PAP)

Accumulation of surfactant within alveolar and bronchiolar spaces
-secondary to impeded or diminished pulmonary macrophage activity

Autoimmune (Ab to GM-CSF), secondary, or hereditary


Pulmonary alveolar proteinosis morphology, presentation and treatment

Surfactant accumulates within lungs making them enlarged and heavy

alveoli filled with granular pink precipitate

Present with cough, producing sputum and gelatinous material

Progressive respiratory failure may occur, at risk for infection

Tx: whole lung lavage and GM-CSF