RHS08 - Pulmonary Pathology 4 Flashcards
(36 cards)
Define bronchiectasis. What other disease is it similar to?
Bronchiectasis - permanent dilation of the bronchi and terminal bronchioles secondary to destruction of supporting tissue
Very similar to emphysema which occurs distal to the terminal bronchioles.
List the major etiologies of bronchiectasis
- Bronchial obstruction leading to mucus build-up lead to chronic infection
- Congenital/Hereditary conditions (CF) leading to impairment of defense mechanisms and increased likelihood of infection
- Severe necrotizing/suppurative pneumonias (s. aureus, klebsiella spp.)
Describe the pathogenesis of bronchiectasis.
- One of the etiologies leads to a severe or chronic infection
- Infection weakens the bronchial walls
- Bronchial walls dilate
Describe the gross morphology of bronchiectasis.
- Dilated airways which can be followed to the pleural surfaces and can appear as cysts filled with mucopurulent secretions
Refer to image
Describe the histological findings in bronchiectasis
- Severe acute and chronic inflammatory exudate in the bronchial walls (refer to image)
What are the clinical findings in bronchiectasis?
- Fever
- Productive cough with lots of purulent sputum
- Typical obstructive disease findings on spirometry and CXR
What is Kartagener Syndrome? What diseases can it cause?
- AKA - Primary Ciliary Dyskinesia
- An autosomal recessive disorder of ciliary microtubules leading to structural abnormalities and impaired ciliary movement
- Leads to bronchiectasis due to the impaired mucociliary escalator causing persistent infections
- Leads to sterility due to the decreased mobility of spermatazoa
- Can lead to situs inversus due to impaired movement of cells during embryogenesis.
Give the definition of interstitial lung disease and its AKAs.
Heterogeneous group of lung parenchymal disorders with common clinical, radiologic, physiologic, and pathologic features. The halmark of those features being involvement of the intersitium.
- Infiltrative Lung Disease - cell and non-cell elements infiltrate the alveoli and septa
- Restrictive Lung Disease - reduced TLC
- Diffuse Parenchymal Lung Disease (DPLD) - it may also involve the alveolar space
What does the lung interstitium consist of?
- Endothelial and Epithelium basement membranes
- Collagen
- Elastin
- Fibroblasts
- Scattered mononuclear inflammatory cells
Describe the general pathogenesis for all interstitial lung diseases
- Something damages the pneumocytes and endothelial cells, causing alveolitis
- If the cause of the damage is not stopped, progressive alveolar injury occurs
- Leukocytes begin releasing cytokines which stimulates interstitial fibrosis. This lowers lung compliance and elasticity
What are the general features of interstitial lung diseases?
- FIBROSIS
- Decreased lung compliance, making breathing difficulty
- Dry cough
- Increased interstitial markings on CXR
- Damage to interstitium leading to a V-Q mismatch and hypoxia
- Progression to respiratory failure with pulmonary HTN and cor pulmonale
List the 4 major categories of interstitial lung disease and the diseases within those categories.
- Fibrosing
- Idiopathic Pulmonary Fibrosis (IPF)(UIP), Non Specific Interstitial Pneumonia (NSIP), Cryptogenic Organizing Pneumonia (COP), Pneumoconiosis
- Granulomatous
- Sarcoidosis, Hypersensitivity Pneumonia (HP)
- Eosinophilic
- Loeffler Syndrome, Drug/Allergy Related, Chronic eosinophilic pneumonia
- Smoking Related
- Desquamative Interstitial Pneumonia (DIP), Respiratory Bronchiolitis Interstitial Lung Disease (RB ILD)
What is Usual Interstitial Pneumonia (UIP)? When is it usually seen?
UIP is a pattern of fibrosis with a distinct radiological and histological presentation seen most commonly in Idiopathic Pulmonary Fibrosis (IPF), but is also seen in Asbestosis and Collagen Vascular Disease (CVD). It is not a pneumonia (lung infection)
Define IPF? Does IPF affect males or females more? Does it affect the young or elderly more? What is the survival rate and treatment plan?
Idiopathic Pulmonary Fibrosis is a restrictive lung disease of unknown etiology that is characterized by relentlessly progressive bilateral interstitial fibrosis with a UIP (usual interstitial pneumonia) presentation.
It affects men more than women and over 2/3 of patients are over the age of 60
Lung transplantation is the only option and, without one, patient generally only survive for 3 years
Describe the histological appearance of UIP
- Geographic (spatial) heterogeneity - parts of the lung micrograph will have fibrosis while others will not
- Temporal heterogeneity - within the fibrotic parts of the lung, some of the fibrosis will be older and some younger.
- Honeycomb change - cystic spaces will be present which can be lined by either Type II pneumocytes or respiratory epithelium
Refer to image - left image demonstrates spatial heterogeneity and the right demonstrates temporal heterogeneity and honeycomb change.
Describe the ragiographic and gross appearance of UIP.
- Gross Morphology - on the surface, the pleura has a cobblestoned appearance. On a cut section, firm, fibrotic parenchyma can be seen with honeycomb cysts
- CXR shows increased interstitial markings bilaterally in the lower lobes and periphery
- Horizontal CT shows the honeycomb appearance from the cysts
Refer to images
What is nonspecific interstitial pneumonia (NSIP)? What is its etiology? What demographic does it usually affect?
NSIP is kind of a diagnosis of exclusion, It has interstitial fibrosis, so it’s definitely a restrictive lung disease, but its histology doesn’t fit the description of any of the other lung diseaes.
It has an unknown etiology and typically affects youger people.
Describe the histological appearance of NSIP.
- Two Variants
- Cellular Variant which has chronic inflammation with lymphocyte infiltrates
- Fibrosing Variant which has uniform fibrosis with a chicken-wire appearance
There is no honeycomb change or fibroblast foci as seen with UIP
What is the general prognosis and treatment plan for NSIP?
Typically, the prognosis is better than the other interstitial diseases, especially with the cellular variant (because gas transport is less hindered)
Treatment varies - some respond to steroids while other respond to immunomodulatory therapies
What is organizing pneumonia and cryptogenic organizing pneumonia? Give etiology, clinical features, and radiographic findings.
Organizing pneumonia is an interstitial lung disease pattern that presents with a cough and dyspnea. On radiography, it presents with patchy peribronchial or subpleural consolidation. It can be seen following infectious pneumonia, lung or bone marrow transplantation, or collage vascular diseases.
If the cause is not known, it is referred to as cryptogenic organizing pneumonia.
Discribe the histological appearance of organizing and cryptogenic organizing pneumonia.
- Presence of Masson bodies, which are plugs of loose fibroblastic tissue filling alveolar spaces
- The architecture of the alveoli are not destroyed
What is the treatment plan for organizing pneumonias?
They usually recover spontaneously or with steroid treatment
What are collagen vascular diseases (CVD) and why do they matter for lung pathology?
A CVD is an autoimmune disease that attacks collagen, resulting in systemic affects. It commonly affects lung tissue and can present with some common pathologic patterns:
- UIP
- NSIP
- Organizing Pneumonia
- Bronchiolitis +/- fibrosis
- LIP
So CVD has to be ruled out to diagnose the above definitively
What is acute interstitial pneumonia (AIP)? What is it AKA?
AKA Hamman Rich Syndrome. It is a very aggressive form of interstiitial lung disease which presents with diffuse alveolar damage and hyaline membranes, similar to ARDS/DAD.
May also occur as an acute phase of IPF
