Restrictive Lung Disease Flashcards
What is the primary issue in restrictive lung diseases?
Decreased TLC
Normal FEV1/FVC ratio
Could be due to fibrosis of the lung or a chest wall disorder preventing expansion
What is seen on histology of restrictive lung diseases that is not seen in obstructive diseases?
Fibrosis
Interstitial Lung Disease
Symptoms
Reduced compliance of lungs
Dyspnea
End inspiratory crackles
Hypoxia
Could eventually cause pulmonary HTN and cor pulmonale
Interstitial Lung Disease
What is the end stage pathology appearance?
Honeycomb lung
Fibrosis causing an appearance of cystic spaces (but not like emphysema)
Describe the pathogenesis of Idiopathic Pulmonary Fibrosis
Repeated epithelial activation/injury by some unidentified agent causes release of TGF-B. Leads to abnormal epithelial repair.
Eventually, this causes fibroblastic proliferation and collagen deposition in the lungs, leading to pulmonary fibrosis
What is the morphology of Idiopathic Pulmonary Fibrosis?
Cobblestone lung
(Scarring of the pleural surface)
Patchy interstitial fibrosis
Non-uniform, varying in intensity and age
Get Honeycomb fibrosis and cystic spaces lined by bronchiolar epithelium
Idiopathic Pulmonary Fibrosis
Where do the cystically dilated airspaces tend to appear?
Lower lobe and subpleural areas
Idiopathic Pulmonary Fibrosis
What stain might you use to identify collagen deposition?
Trichrome stain
Idiopathic Pulmonary Fibrosis
Symptoms
Dyspnea on exertion
Dry cough
Velcro crackles
Deterioration of lung
Idiopathic Pulmonary Fibrosis
What is the only definitive treatment?
Lung transplant
Idiopathic Pulmonary Fibrosis
Prognosis
Mean survival time is less than 3 years
What is Pneumoconioses?
Accumulation of dust in the lungs and tissue reaction to its presence
What is the most prevalent occupational disease?
Silicosis
What is the size of the most dangerous particles for Pneumoconioses? Why?
1-5 microns
They can reach the terminal small airways, air sacs, and settle in the linings, but are too big to be ingested by alveolar macrophages
Describe the basic pathogenesis of Pneumoconioses
Macrophages endocytose trapped particles in the small airways. Reactive particles tigger release of inflammatory mediators from macrophages, leading to fibrogenesis and collagen deposition
Anthracosis
Who is most likely to get it?
Smokers
Urban dwellers
Coal miners
Describe the pathogenesis of Anthracosis
Inhaled carbon pigment is engulfed by alveolar and interstitial macrophages
Deposits in the lungs and lymph nodes (get black nodes on lungs and the lymph nodes are black)
Anthracosis
Prognosis
No sequelae associated with Anthracosis
If it develops over time, it may cause Simple Coal Workers Pneumoconiosis
Simple Coal Workers Pneumoconiosis
What is the appearance?
Accumulation of dust-laden macrophages with some patchy fibrosis
Progressive Massive Fibrosis
What is the appearance?
Coal nodules coalesce in the lungs
Get fibrotic heavy black tissue masses
Caplan Syndrome
What are the two diseases associated with it? What happens?
Form of Coal Worker Pneumoconiosis associated with Rheumatoid Arthritis
Fibrotic lesions form and they get fibrotic nodules with a tendency to cavitate
Silicosis
What is the characteristic appearance of the nodules?
Whorled hyalinized collagen (whirls of concentric collagen appear)
Silicosis
Where may the fibrotic lesions appear?
They tend to affect the upper lobe
The fibrotic lesions may spread to hilar lymph nodes. The lymph node capsule tends to get calcified (“eggshell” calcification)
Silicosis
What sequelae does it cause?
Increased susceptibility to tuberculosis (suppressed cell mediated immunity)
Dyspnea
Pulm HTN
Cor pulmonale
Asbestos is a strong carcinogen. What cancers may it cause?
Bronchogenic carcinoma
Laryngeal carcinoma
Malignant Meseltheliomas
Asbestos
What may been seen characteristically on H&E?
Asbestos body (ferrogenous body) Beaded structure with a knobby head (Intracellular iron deposits on the asbestos body coats it)
How much higher is risk for lung cancer with asbestos exposure? With both asbestos and tobacco?
5x with asbestos alone
55x with both
Sarcoidosis
What is seen on histology?
Non-caseating granulomas (with lymphocytes, epithelioid histiocytes, and giant cells)
You may see the granulomas in the bronchiole epithelium, alveolar airspace, lymph nodes
Sarcoidosis
What is seen on CXR?
Bilateral hilar lymphadenopathy
Describe the pathogenesis of Sarcoidosis
Some antigen in a patient with genetic susceptibility results in an abnormally large IFN-y and TNF-a response
Results in formation of granulomas, which may resolve or progress to chronicity and fibrosis
Sarcoidosis
What is a Schaumann body?
Concentration of calcium and proteins within giant cells
Sarcoidosis
What is an asteroid body?
Stellate inclusions in the granuloma
Sarcoidosis
What patients are more likely to get it? Where?
Young adults, mostly in upper lobe
Young asymptomatic African American woman is a common boards prompt
Sarcoidosis
What tests are done to confirm the diagnosis?
It is a diagnosis of exclusion (test for infection and other granuloma causes first)
Do a transbronchial biopsy with 4 samples submitted
Sarcoidosis
Symptoms
Often asymptomatic SOB Dry cough Fever Fatigue Night sweats Weight loss Anorexia Diffuse intersititial fibrosis
What are some systemic involvements of Sarcoidosis?
Eye- Uveitis
Skin - Erythema nodosum
Heart- Restrictive cardiomyopathy
Bell’s Palsy- CN VII
Sarcoidosis
List some lab/diagnostic abnormalities
Elevated serum ACE
Hypercalcemia
Anergy to common skin test antigens
Why does Sarcoidosis cause hypercalcemia?
Granulomas can make the hydroxylase enzyme to make 1,25 (OH)2 Vit D3, which increases Ca2+ absorption
