10-12 DSA Interstitial Lung Disease by Kinder Flashcards
What are interstitial lung diseases?
•Large group of disorders that affect the alveolar wall that ultimately lead to diffuse scarring or fibrosis
What is a misnomer for interstitial lung disease?
•Misnomer: Interstitial lung disease affects all components of the alveolar wall which include epithelial cells, endothelial cells, and the interstitium
What are the clinical manifestations of interstitial lung disease?
- Clinical Manifestations
- Dyspnea, noticed initially on exertion
- Nonproductive cough
- Crackles prominent at lung bases
- Clubbing may be present
What is the pathophysiology of interstitial lung disease?
- Pathophysiology
- Decreased compliance (increased stiffness) of lungs
- Decreased lung volumes
- Loss of alveolar-capillary surface area resulting in impaired measured diffusion
- Abnormalities in small airway function without generalized airflow obstruction
- Hypoxemia without CO2 retention
- Pulmonary hypertension
What will CXR show for ILD?
- Reticular – increased linear markings
- Reticulonodular – increased linear and small nodular markings
- 10% have normal radiographic findings
What will high-resolution computed tomography show for ILD?
- High-resolution computed tomography (HRCT)
- Can distinguish inflammation from fibrosis
- Picks up early changes
- Specific pattern may be suggestive of a particular diagnosis
What are the tissue specimens needed for Dx for ILD?
- Tissue specimens for diagnosis
- Thorascopic lung biopsy
- Transbronchial biopsy via flexible bronchoscopy
- Bronchoalveolar lavage
What will PFT show with ILD?
- PFT
- Restrictive pattern
- Decreased lung volumes
- hypoxia
What is the known etiology for ILD?
- Classification
- Known Etiology ~ 35%
- Inhaled inorganic dusts (pneumoconiosis such as asbestosis or silicosis)
- Organic antigens ( hypersensitivity pneumonitis)
What are some unknown/idiopathic etiologies for ILD?
- Unknown Etiology ~65%
- Idiopathic interstitial pneumonias
- Connective tissue diseases (rheumatic disease)
- Sarcoidosis
What are some more rare etiologies of ILD?
- Unknown Etiology – continued
- Less Common
- Pulmonary Langerhans cell histiocytosis
- Lymphangioleiomyomatosis
- Goodpasture’s Syndrome
- Wegener’s granulmomatosis
- Chronic eosinophilic pneumonia
- Pulmonary alveolar proteinosis
What are the 2 pathological processes behind ILD? Which process occurs first?
- Pathologic Processes
- 1) inflammatory process in the alveolar spaces – alveolitis
- 2) scarring – fibrosis
- Both processes often occur simultaneously
What is a granuloma?
•Granuloma : localized collection of cells called epithelioid histocytes (phagocytic or macrophage), generally accompanied by T-lymphocytes, multinucleated giant cells. Noncaseating in interstitial lung diseases. Examples include hypersensitivity pneumonitis and sarcoidosis
What are the idiopathic interstitial pneumonias?
- Usual interstitial pneumonia
- Desquamative interstitial pneumonia
- Respiratory bronchiolitis interstitial lung disease
- Nonspecific interstitial pneumonia
- Acute interstitial pneumonia
- Cryptogenic organizing pneumonia
- Lymphocytic interstitial pneumonia
What are the characteristics of usual interstitial pneumonia?
- Patchy areas of parenchymal fibrosis and interstitial inflammation interspersed between areas of relatively preserved lung tissue
- Fibrosis is the most prominent component of the pathology
- Honeycombing – cystic airspace from retraction of surrounding fibrotic tissue
- Most important disorder in this category is idiopathic pulmonary fibrosis
What are some important pathological points behind desquamative interstitial pneumonia?
- More homogenous than UIP
- Large number of intraalveolar mononuclear cells
- Less prominent inflammation and little associated fibrosis
- Uniform process
- Minimal architectural distortion
- Pigmented macrophages in respiratory bronchioles secondary to smoking
What is respiratory bronchiolitis interstitial lung disease related to?
desquam. interstit. pneumonia (DIP)
What are some pathological associations with resp. bronchiolitis interstitial lung disease?
- Associated with pigmented macrophages which are present within the lumen of respiratory bronchioles
- Interstitial inflammation is not present
What is a major risk for resp. bronchiolitis interstitial lung disease?
- Almost always associated with smoking
- Most important intervention is smoking cessation
What are some pertinent pathological processes with nonspecific interstitial pneumonia?
- Mononuculear cell infiltration within the alveolar walls
- Uniform process
- Fibrosis is variable, but less than UIP
- Idiopathic or connective tissue disorder
- Better prognosis
What are the pathological changes associated with acute interstitial pneumonia?
- Organizing or fibrotic stage of alveolar damage, which is the histologic pattern seen in ARDS.
- No initial trigger identified.
What are the histological changes associated with acute interstitial pneumonia?
•Histology shows fibroblast proliferation and type II pneumocyte hyperplasia in the setting of what appears to be organizing alveolar damage
