Pulmonary Pathology III Flashcards
What is the general feature of restrictive lung disease?
Decreased total lung capacity
What are the two categories of restrictive lung disease?
- Interstitial lung disease
- Chest wall disease
What are the characteristics of interstitial lung disease?
Group of disorders which result in inflammation and fibrosis of alveolar walls (septa) with similar features: -Dyspnea -Tachypnea -Decreased lung volume and compliance -Diffuse infiltration by small nodules -"Honeycomb lung" at the end stage
What are the categories of interstitial lung disease?
- Fibrosing
- Granulomatous
- Eosinophilic
- Smoking related
What is Idiopathic Pulmonary Fibrosis AKA?
Usual interstitial pneumonia
What is the pathogenesis of IPF?
Repeated cycles of epithelial activation/injury by some unidentified agent lead to abnormal epithelial repair and fibroblastic proliferation resulting in fibrosis with increased collagen from wound healing
What are the gross findings in IPF?
Scarring of pleural surfaces - cobble stoned
Fibrosis of lung parenchyma which appear as firm, rubbery, white areas
Findings most prominent subpleural and along interlobular septa
What is the histology of IPF?
Honeycomb fibrosis represents the destruction of alveolar architecture and formation of cystic spaces lined by pneumocytes type II and bronchial epithelium
What will stain areas of fibrosis in IPF blue?
Trichrome Stain
What is the typical patient of IPF?
Male between 40-70 years
What is the prognosis of IPF and definitive treatment for it?
Definitive treatment is lung transplant
Mean survival is 3 years after diagnosis
Pneumoconiosis
The accumulation of dust in the lungs and the tissue reaction to its presence
Agent in Siderosis
Iron - welding
Agent in Anthracosis
Coal - mining
Agent in Silicosis
Silica - sand blasting
Agent in Asbestosis
Asbestos - ship building
What size particles are the most dangerous when inhaled and why?
1-5 m particles most dangerous - they can reach terminal small airways, air sacs, settle in linings
Pathogenesis of Pneumoconiosis
Macrophages endocytose and trap particles. Reactive particles trigger release of inflammatory mediators from macrophages which initiate fibroblast proliferation and activation. End result – collagen deposition and fibrosis.
What are the 3 states of Coal Worker’s Pneumoconiosis?
Anthracosis
Simple coal worker’s pneumoconiosis
Progressive massive fibrosis
What is the pathogenesis of anthracosis?
Inhaled carbon pigment is engulfed by alveolar/interstitial macrophages. Accumulates in connective tissue, pleural lymphatics, lymph nodes - no sequelae
What is the patient population of anthracosis?
Seen in urban dwellers, tobacco smokers and coal miners
What is seen with simple coal worker’s pneumoconiosis?
Coal macules, nodules with accumulations of dust-laden macrophages and fibrosis - not many other symptoms though
Pathogenesis of Progressive Massive Fibrosis
Results from coalescence of coal nodules leading to haphazard fibrosis, large scars (2-10cm) with dense collagen and pigment leading to: progressive dyspnea, pulmonary dysfunction, pulmonary hypertension, cor pulmonale
What is the finding in progressive massive fibrosis - anthracosis?
“Black Lung”
What is Caplan Syndrome and what is it AKA?
AKA rheumatoid pneumoconiosis
Form of Coal Worker Pneumoconiosis associated with rheumatoid arthritis
What is the most prevalent occupational disease?
Silicosis
Silicosis
Inhalation of crystalline silica causes macrophage activation and the release of cytokines that are ultimately fibrogenic
Simple Nodular Silicosis
Upper zones of lungs with concentric hyalinized collagen with a whorled appearance
Fibrotic lesions may be present in hilar lymph nodes
Progressive Massive Fibrosis - Silicosis
Coalescence of nodules that can lead to: progressive dyspnea, pulmonary dysfunction, pulmonary hypertension, cor pulmonale
What disease is silicosis associated with?
Silicosis is associated with increased susceptibility to tuberculosis. It is postulated that silicosis depresses cell mediated immunity and silica may inhibit ability of pulmonary macrophages to kill phagocytosed myocbacteria
What are the effects of asbestos?
- Acts as tumor initiator and promoter (mediated by reactive free radicals)
- Adsorbs toxic chemicals (tobacco smoke)
- Fibrinogenic effect
What are the plethora of asbestos effects?
Interstitial fibrosis (asbestosis) Localized fibrous plaques - pleural plaques Diffuse fibrosis of pleura Pleural effusions Bronchogenic carcinoma Malignant mesothelioma Largyngeal carcinoma
What is the interaction of asbestos with smoking?
Synergistically increased risk of bronchogenic cancer with smoking - 55x more likely chance of cancer
What is the most common manifestation of asbestos exposure?
Localized fibrous pleural plaques - well circumscribed plaques of dense collagen usually on parietal pleura and
domes of diaphragm.
What cancer is highly related to asbestos but NOT smoking?
Mesothelioma
What is the pathogenesis of malignant mesothelioma?
Asbestos fibers settle near mesothelium
Reactive oxygen free radicals induce DNA damage
What stain will mesothelioma be positive for?
Positive staining for calretinin
Sarcoidosis
Multisystem disease of unknown etiology
Characterized by non-caseating granulomas
How is sarcoidosis diagnosed?
Diagnosis of exclusion because other diseases may present as non-caseating granulomas: TB, fungal infection, berylliosis
Pathogenesis of Sarcoidosis
Unknown, however evidence suggests disordered immune regulation in genetically predisposed individuals exposed to certain environmental agents - hypothesized to be CD4 T-cell driven
What are some findings with sarcoidosis?
- Uveitis
- Bell’s Palsy - CN VII
- Pulmonary interstitial fibrosis
- Restrictive cardiomyopathy
- Hypercalcemia
- Asteroid and Schaumann bodies
What are Asteroid and Schaumann bodies?
- Schauman bodies – laminated concretions composed of calcium and proteins
- Asteroid bodies – stellate inclusions
What is the typical patient of sarcoidosis?
Young adult - under the age of 40
African Americans, Danish and Swedish
Why is there hypercalcemia in sarcoidosis?
Granulomas autonomously convert 25-hydroxyvitamin D to 1,25-dihydroxyvitamin D which increases calcium absorption
A 66-year-old man has had increasing dyspnea for the past year. He is a smoker. He is retired from the construction business. There are some rales auscultated in both lungs on physical examination. A chest radiograph reveals bilateral diaphragmatic pleural plaques with focal calcification as well as diffuse interstitial lung disease. A sputum cytology shows no atypical cells. Pulmonary function studies reveal a low FVC and a normal
FEV1/FVC ratio. These findings are most likely to suggest prior exposure to which of the following environmental agents?
A Cotton fibers B Silica dust C Fumes with iron particles D Asbestos crystals E Beryllium
D Asbestos crystals
Hypersensitivity Pneumonitis
Abnormal hypersensitivity response from spores of thermophilic bacteria, fungi, animal proteins, bacterial products - Immunologically mediated response to an extrinsic antigen that involves both immune complex and delayed type hypersensitivity reactions (Type III and IV)
