10-12 DSA Interstitial Lung Disease by Kinder

Question 1

What are interstitial lung diseases?

Answer 1

•Large group of disorders that affect the alveolar wall that ultimately lead to diffuse scarring or fibrosis

Question 2

What is a misnomer for interstitial lung disease?

Answer 2

•Misnomer: Interstitial lung disease affects all components of the alveolar wall which include epithelial cells, endothelial cells, and the interstitium

Question 3

What are the clinical manifestations of interstitial lung disease?

Answer 3

• Clinical Manifestations
• Dyspnea, noticed initially on exertion
• Nonproductive cough
• Crackles prominent at lung bases
• Clubbing may be present

Question 4

What is the pathophysiology of interstitial lung disease?

Answer 4

• 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

Question 5

What will CXR show for ILD?

Answer 5

• Reticular – increased linear markings
• Reticulonodular – increased linear and small nodular markings
• 10% have normal radiographic findings

Question 6

What will high-resolution computed tomography show for ILD?

Answer 6

• High-resolution computed tomography (HRCT)
• Can distinguish inflammation from fibrosis
• Picks up early changes
• Specific pattern may be suggestive of a particular diagnosis

Question 7

What are the tissue specimens needed for Dx for ILD?

Answer 7

• Tissue specimens for diagnosis
• Thorascopic lung biopsy
• Transbronchial biopsy via flexible bronchoscopy
• Bronchoalveolar lavage

Question 8

What will PFT show with ILD?

Answer 8

• PFT
• Restrictive pattern
• Decreased lung volumes
• hypoxia

Question 9

What is the known etiology for ILD?

Answer 9

• Classification
• Known Etiology ~ 35%
• Inhaled inorganic dusts (pneumoconiosis such as asbestosis or silicosis)
• Organic antigens ( hypersensitivity pneumonitis)

Question 10

What are some unknown/idiopathic etiologies for ILD?

Answer 10

• Unknown Etiology ~65%
• Idiopathic interstitial pneumonias
• Connective tissue diseases (rheumatic disease)
• Sarcoidosis

Question 11

What are some more rare etiologies of ILD?

Answer 11

• Unknown Etiology – continued
• Less Common
• Pulmonary Langerhans cell histiocytosis
• Lymphangioleiomyomatosis
• Goodpasture’s Syndrome
• Wegener’s granulmomatosis
• Chronic eosinophilic pneumonia
• Pulmonary alveolar proteinosis

Question 12

What are the 2 pathological processes behind ILD? Which process occurs first?

Answer 12

• Pathologic Processes
• 1) inflammatory process in the alveolar spaces – alveolitis
• 2) scarring – fibrosis
• Both processes often occur simultaneously

Question 13

What is a granuloma?

Answer 13

•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

Question 14

What are the idiopathic interstitial pneumonias?

Answer 14

• Usual interstitial pneumonia
• Desquamative interstitial pneumonia
• Respiratory bronchiolitis interstitial lung disease
• Nonspecific interstitial pneumonia
• Acute interstitial pneumonia
• Cryptogenic organizing pneumonia
• Lymphocytic interstitial pneumonia

Question 15

What are the characteristics of usual interstitial pneumonia?

Answer 15

• 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

Question 16

What are some important pathological points behind desquamative interstitial pneumonia?

Answer 16

• 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

Question 17

What is respiratory bronchiolitis interstitial lung disease related to?

Answer 17

desquam. interstit. pneumonia (DIP)

Question 18

What are some pathological associations with resp. bronchiolitis interstitial lung disease?

Answer 18

• Associated with pigmented macrophages which are present within the lumen of respiratory bronchioles
• Interstitial inflammation is not present

Question 19

What is a major risk for resp. bronchiolitis interstitial lung disease?

Answer 19

• Almost always associated with smoking
• Most important intervention is smoking cessation

Question 20

What are some pertinent pathological processes with nonspecific interstitial pneumonia?

Answer 20

• Mononuculear cell infiltration within the alveolar walls
• Uniform process
• Fibrosis is variable, but less than UIP
• Idiopathic or connective tissue disorder
• Better prognosis

Question 21

What are the pathological changes associated with acute interstitial pneumonia?

Answer 21

• Organizing or fibrotic stage of alveolar damage, which is the histologic pattern seen in ARDS.
• No initial trigger identified.

Question 22

What are the histological changes associated with acute interstitial pneumonia?

Answer 22

•Histology shows fibroblast proliferation and type II pneumocyte hyperplasia in the setting of what appears to be organizing alveolar damage