Flashcards in The Lungs 2 Deck (87):
What is the "hallmark" of diffuse interstitial (restrictive/infiltrative) lung diseases?
Reduced lung compliance/increased stiffness
Diffuse interstitial (restrictive/infiltrative) lung diseases are characterized predominantly by diffuse and chronic involvement of the pulmonary __________ _______, principally the most peripheral and delicate interstitium in the ________ _______.
involvement of the pulmonary connective tissue in the delicate interstitium of the alveolar walls.
What two things are seen on CXR in a patient with diffuse interstitial (restrictive/infiltrative) lung disease?
1. Diffuse infiltration by small nodules.
2. Ground-glass shadows (irregular lines)
Diffuse interstitial (restrictive/infiltrative) lung disease eventually leads to diffuse interstitial _______ with or without _________.
interstitial fibrosis with or without honeycombing
What is the earliest, most common manifestation of diffuse interstitial (restrictive/infiltrative) lung disease?
If alveolitis is mild and self limited, can resolution and restoration of normal architecture be acheived?
Where exactly in the lungs do inflammatory and immune cells accumulate in the setting of alveolitis? Specifically which cells are involved?
Fibroblasts, lymphocytes, macrophages, and neutrophils are found within the alveolar walls and spaces
What is the key event in the pathogenesis to interstitial fibrosis from alveolitis?
Activation of pulmonary macrophages.
Once activated, what to macrophages do that contributes to the pathogenesis of chronic restrictive lung disease and fibrosis? (3 things)
What therefore happens to the pneumocytes?
1. They recruit neutrophils
2. They release oxidants and proteases (and so do the recruited neutrophils)
3. They release fibrogenic and chemotactic cytokines that activate fibroblasts
These factors injure type I pneumocytes and cause hypertrophy and hyperplasia of type II pneumocytes
Define idiopathic pulmonary fibrosis aka cryptogenic fibrosing alveolitis.
A type of restrictive lung disease of unknown etiology
Describe the general pathogenesis of idiopathic pulmonary fibrosis aka cryptogenic fibrosing alveolitis.
Repeated epithelial activation/injury --> abnormal repair --> increased fibroblast and myofibroblast proliferation --> fibroblastic loci
Which GF plays an important role in the pathogenesis of idiopathic pulmonary fibrosis aka cryptogenic fibrosing alveolitis? How does it work?
TGF-beta1 activates fibroblasts and myofibroblasts to make ECM stuff leading to fibrosis
What morphological change typifies idiopathic pulmonary fibrosis aka cryptogenic fibrosing alveolitis?
Patchy but progressive bilateral interstitial fibrosis.
The radiologic and histologic pattern of lung fibrosis is known as what?
Usual interstitial pneumonia (UIP)
Describe the two gross morphological changes seen in usual interstitial pneumonia.
Pleural surface has a cobblestone appearance due to retraction of scars along the interlobular septa.
Cut surface shows fibrosis (firm, rubbery white areas), especially in the SUBPLEURAL region of the lower lobes and along the CT septa.
Describe four histologic changes seen in usual interstitial pneumonia.
1. PATCHY INTERSTITIAL FIBROSIS interspersed with normal tissue.
2. Alveolar septal infiltration of mostly lymphocytes, occasional plasma cells, and occasional eosinophils.
3. Severe cases exhibit alveolar collapse due to dense fibrosis.
4. Cystic spaces are lined by hyperplastic type II pneumocytes or bronchial epithelium (known as honeycomb fibrosis).
What is the difference between early and late lesions in the lungs of a person with lung fibrosis and usual interstitial pneumonia?
Early lesions have lots of proliferating fibroblasts (fibroblastic loci).
Late lesions become less cellular and more collagenous.
Advanced cases of idiopathic pulmonary fibrosis result in severe ______ and ______.
hypoxemia and cyanosis
Is usual interstitial pneumonia a common type of interstitial pneumonia? Which gender is most often affected? How old are most people with the disease?
Yeah its a common type. Males > females. 2/3 of pts are over 60.
Name three clinical features of UIP.
1. Gradual dyspnea upon exertion.
2. Dry cough with velcro-like crackles during inspiration.
3. Cyanosis, cor pulmonale, and peripheral edema may develop in late stages.
What is the mean survival rate of UIP and what is the definitive treatment?
3 years or less. Tx is lung transplantation
Is pneumoconioses a restrictive, or obstructive lung disease?
What is pneumoconioses?
Non-neoplastic lung reaction to inhalation of crap.
Name three mineral dusts that can contribute to pneumoconioses.
1. Coal dust
What is the most important factor in the pathogenesis of pneumoconioses?
The capacity of the inhaled particulates to stimulate fibrosis.
What sized particles are most dangerous regarding the pathogenesis of pneumococonioses? Why?
1 to 5 micrometers (small ones) because they get lodged at the bifurcations of the distal airways
Which cellular component is key in the initiation and perpetuation of lung injury and fibrosis in the pathogenesis of pneumococonioses?
What is asbestosis?
A type of pneumococonioses: Diffuse interstitial fibrosis (restrictive) from inhalation of asbestos fibers.
Describe the pathogenesis of asbestosis.
Macrophages try to eat the asbestos fibers. Some fibers get into the interstitium. Macrophages get activated, and they activate firboblasts.
What is an asbestos body? How does it stain?
A thin asbestos fiber surrounded by a beaded iron-protein coat.
Stains golden-brown in routing H&E and stains strongly with the Prussian blue stain for iron.
How do asbestos bodies form? Where in the lungs are they found?
They form because macrophages coat the fibers with proteins, proteoglycans and ferritin. Found in the walls of bronchioles or within alveolar spaces.
Can an asbestos body be found inside a macrophage?
Name the disease that is associated with large, discrete fibrocalcific plaques on the pleural surface of the diaphragm.
What are the pleural plaques of asbestosis comprised of?
Dense collagen often containing calcium
Which six disease processes are asbestos exposure linked to?
1. Parenchymal interstitial fibrosis (asbestosis).
2. Localized fibrous plaques, or diffuse pleural fibrosis (rare).
3. Pleural effusions.
4. Bronchogenic carcinomas.
5. Malignant pleural and peritoneal mesotheliomas.
6. Laryngeal cancer.
When do symptoms appear after asbestos exposure? What symptom is common?
10-20 years after - worsening dyspnea
Can lung damage from asbestos exposure stay static, progress to CHF, cor pulmonale, or cause death?
Are family members of workers who were exposed to asbestos at an increased risk of cancer?
Does hypersensitivity pneumonitis cause restrictive lung disease?
Name a granulomatous disease that causes interstitial lung fibrosis.
What is sarcoidosis?
A granulomatous disease and a form of chronic interstitial (restrictive) lung disease that affects multiple systems/organs, especially the lungs and lymph nodes.
What cellular mechanism contributes to the pathogenesis of sarcoidosis?
Type 4 reaction to unknown Ag. Driven by CD4+ T cells.
What population within the U.S. is disproportionately affected by sarcoidosis?
African americans:caucasians is 10:1
Describe the morphology of sarcoidosis. (5)
1. Multiple sarcoid granulomas in the interstitium of the lung, along the pleura and interlobular septa and around bronchovascular bundles.
2. Each granuloma has a lot of CD4+ T cells and epitheloid cells.
3. Multinucleated giant cells are present.
4. Laminated fibroblasts surround each granuloma.
5. Asteroid bodies and Schaumann bodies may be present.
What is an asteroid body? What is a Schaumann body?
Both seen in sarcoidosis.
Asteroid body is a star-shaped crystal.
Schaumann body is a small lamellar calfification.
In sarcoidosis, lungs are involved in ____% of patients and the granulomas are eventually replaced by diffuse _______ _______, causing restrictive lung disease.
90% of patients have affected lungs. Granulomas are replaced by diffuse interstitial fibrosis
What are the two types of sarcoidosis? Describe each.
Acute: Abrupt onset, spontaneous remission within two years, responds to steroids.
Chronic: Insidious onset, persistent and/or progressive disease more likely.
___% of sarcoidosis patients recover spontaneously while ____% succumb to progressive fibrosis and cor pulmonale. After lung transplantation, ____% of patients get sarcoidosis in the new lungs.
10-15% get fibrosis
75% of pts get it in new lungs
Bronchopneumonia affects ______ of the lungs, whereas lobar pneumonia affefts entire ______.
bronchopneumonia is patchy
lobar affects entire lobes
Is there a specific lab test to make the diagnosis of sarcoidosis?
What lung disease can Strep. pneumoniae and H. influenzae cause?
Community-acquired acute pneumonia.
What disease can Mycoplasma pneumoniae cause?
Community-acquired atypical pneumonia
What is the most common cause of community-acquired acute pneumonia?
Which populations are more susceptible to infection by strep. pneumoniae?
1. People with underlying chronic disease like COPD, CHF, or DM.
2. People with congenital or acquired Ig defects.
3. People with decreased splenic function.
Describe the morphological changes from pneumococcal lung infection.
1. Lobar or bronchopneumonia may occur.
2. Lower lobes, or the right middle lobe most frequently involved.
3. Four stages (lobar pattern only): Congestion, red hepatization, gray hepatization, and resolution.
Describe each of the four stages of lobar pneumococcal pneumonia.
Congestion: Lobes are heavy and red. Congestion with proteinaceous fluid, scattered neutrophils, and bacteria.
Red hepatization: Liver-like consistency. Alveolar spaces packed with neutrophils, RBCs, and fibrin.
Gray hepatization: Lung is dry, gray, firm due to lysed RBCs. Fibrinosupperative exudate in alveoli.
Resolution: In uncomplicated cases - enzymatic digestion of crud followed by macrophage ingestion.
Describe the morphology of the bronchopneumonic pattern of pneumococcal pneumonia (2).
1. Patches of lesions 3-4cm diameter each.
2. Supperative exudate that fills the bronchi, bronchioles, and alveolar spaces.
What cell type is most prominent in the red hepatization stage of lobar pneumococcal pneumonia?
What type of cancer accounts for the leading cause of cancer death in the U.S.?
Primary lung tumors
Do cancers often metastasize to the lungs?
_________ epithelium is the site of origin for 95% of primary lung carcinomas.
What are the four major histologic types of lung carcinomas?
1. Squamous cell carcinoma
3. Large cell carcinoma
4. Small cell carcinoma
For lung carcinoma treatment purposes, what two categories are patients placed in and why?
Either small cell or large cell. Small cell lung cancers are typically already metastasized and not treatable by surgery, only by chemo and radiation. Non-small cell lung cancer (NSCLC) is best treated surgically and they don't respond to chemo.
Squamous cell carcinomas of the lung make up _____% of all invasive lung cancers in the US and are closely associated with a history of ________.
Where do squamous cell lung carcinomas usually arise?
In major bronchi
How does cigarette smoking cause lung cancer?
Injury to bronchial epithelium --> basal layer regeneration --> metaplasia --> dysplasia --> carcinoma in situ --> invasive tumor
What is the most common cancer type in women and nonsmokers?
Where do adenocarcinomas arise usually?
From the periphery, often associated with pleural fibrosis and subplueral scars
Do adenocarcinomas grow slowly and metastasize at an early stage?
What are the four histologic subtypes of lung adenocarcinomas?
What is the precursor to adenocarcinomas of the lung?
Atypical adenomatous hyperplasia
Describe the changes involved in atypical adenomatous hyperplasia.
Proliferation of cuboidal and low cuboidal cells resembling Clara cells or Type 2 pneumocytes.
Describe histologic characteristics of large cell carcinomas (3).
1. No glandular or squamous differentiation.
2. Large nuclei, prominent nucleoli, moderate amount of cytoplasm.
3. Most likely to evolve from poorly differentiated aednocarcinomas or squamous cell carcinomas.
Large cell carcinomas account for ____% of lung cancers while small cell carinomas account for ___% of lung carcinomas.
large cell 10%
small cell 20%
State three general features of small cell lung carcinomas.
1. Strong association with cig smoking.
2. May have neuroendocrine features (remember Cushings).
3. Grows and metastasizes rapidly - median survival rate is 1 year.
Describe five histologic characteristics of small cell carcinomas.
1. Pale gray, centrally located masses with extensions into the lung parenchyma.
2. Small, round or oval, or spindle-shaped cells with little cytoplasm.
3. Granular nuclear chromatin and no nucleoli.
4. High rate of mitosis.
5. Necrosis within the tumor.
___ to __% of patients with lung cancers develop paraneoplastic syndromes.
3 to 10%
List six paraneoplastic syndromes from lung cancer.
1. PTH --> hypercalcemia (squamous cell carcinoma)
2. Cushing - ACTH
3. ADH secretion
4. Myasthenic syndromes
5. Clubbing of fingers, arthropathy.
6. Hematologic manifestations
What is a bronchial carcinoid?
Low-grade malignant tumor composed of neuroendocrine cells from Kulchitsky cells that line the bronchial mucosa. Resemble intestinal carcinoids.
What is the age of onset of bronchial carcinoids?
What is carcinoid syndrome? Which lung cancer type causes it?
Serotonin and kallikrein that cause attacks of diarrhea, flushing, and cyanosis. Can be caused by bronchial carcinoids.
True or false: Bronchial carcinoids show no gender predilection, are not related to cig smoking, are most often endocrinologically silent, and are often resectable and curable
What is a malignant mesothelioma?
Neoplasm of mesothelial cells in the lung pleura or peritoneum, pericardium, or tunica vaginalis of the testis.
Malignant mesotheliomas are associated with _______ exposure and have a latency period of around ______ years.
asbestos, 20 year latency
What disease does asbestos exposure + cig smoking increase risk for? What does it surprisingly NOT increase risk for?
Increases risk for lung carcinoma but NOT malignant mesothelioma
By what mechanism do mesotheliomas inhibit lung function?
Tumor spreads within chest cavity and compresses lung structures. Pleural fibrosis and plaque formation contribiute.