Pulmonary: Pathology Part III - Restrictive Diseases Flashcards
1
Q
- Characterized by restricive filling of the lung
- ↓ TLC
- ↓ FEV1
- ↓↓ FVC
- ↑ (FEV1/FVC) ratio > 80%
- Most commonly due to Interstitial diseases of the lung (Peripheral Hypoventilation, Normal A-a gradient)
- May also arise w/ chest wall abnormalities (e.g. scoliosis, massive obesity)
- Poor muscular effor (Polio, Myasthenia gravis)
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Restrictive Diseases Basic Principles
2
Q
- Fibrosis of Lung interstitium - disease of exlusion
- Etiology unknown. Likely related to cyclical lung injury: TGF-β from injured pneumocytes induces fibrosis
- 2nd causes: drugs (Bleomycin and Amioderone) and XRT must be excluded
- Dx: Progressive Dyspnea and Cough
- Fibrosis on Lung CT; init. in Subpleural patches but eventually resutls in diffuse fibrosis w/ end-stage ‘Honeycomb’ lung
- Tx: Lung transplantation
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Idiopathic Pulmonary Fibrosis
3
Q
- Interstitial fibrosis due to Chronic Occupational exposure
- Requires chronic exposure to Small particles that are Fibrogenic
- Alveolar Macrophages engulf foreign particles and Induce fibrosis
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Pneumoconioses
4
Q
- Systemic disease, Nonnectrotizing and
Noncaseating granulomas - Classically seen in African American females
- Etiology unknown; likely due to CD4+ T-cell response to an unknown antigen
- Granulomas involve Hilar lymph nodes and Lung
→ Restricive lung disease - Stellate inclusions (‘Asteroid bodies’) w/in giant cells of Granulomas - Uvea (uveitis), Skin (cutaneous nodules or erythema nodosum), Salivary and Lacrimal glands
- Dyspnea, Cough, Elevated Serum ACE, Hypercalemia (1-α Hyrdoxylase converts Vit. D to active form)
- Tx: Steroids, resolves spontaneously w/out Tx
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Sarcoidosis
5
Q
- Upper Lobes - Anthracosis - asymptomatic condition: urban dwellings and sooty air
- Carbon / Coal dust; seen in coal miners
- Massive exposure leads to diffuse fibrosis (‘black lung’)
- A/w Rheumatoid arthritis (Caplan syndrome)
- Mild exposure (pollution) results in Anthracosis (collection of Carbon-laden Macrophages); not clincially significant
→ Inflammation and Fibrosis
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Coal Workers’ Pneumoconiosis
6
Q
- Upper Lobes - “Eggshell” Calcification of Hilar Lymph nodes
- Silica; seen in sandblasters and silica miners and a/w foundries
- Fibrotic nodules in Upper Lobes of the Lung
- **Increased risk for TB **/ Bronchogenic Carcinoma
- Silica disrupts/impairs Phagolysosome formation by Macrophages release fibrogenic factors → Fibrosis (Hilar Lymph Nodes)
- Only disease** ↑ risk for TB in Upper Lobe**
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Silicosis
7
Q
- Beryllium; seen in beryllium miners and workers in the Aerospace industry
- Noncaseating granulomas in the Lung
- Hilar lymph nodes, and systemic organs
- Increased risk of Lung cancer
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Berylliosis
8
Q
- Lower Lobes
- Asbestos fibers; seen in construction workers, plumbers, roofers, and shipyard workers
- Pulmonary Fibrosis of Lung and Pleura (‘Ivory white’ plaques) w/ increased risk for Bronchogenic Lung carcinoma and Mesothelioma (Hilar lymph nodes_
- Lung carcinoma is more common than Mesothelioma in exposed individuals
- Lesions may contain Long, Golden-brown fibers w/ associated Iron (Ferruginous) (Asbestos bodies + Pulmonary fibrosis - confirm exposure to Asbestos) - Parietal Plueral Plaques
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Asbestosis
9
Q
- Granulomatous w/ Eosinophils Rxn to Inhaled organic Antigens (Pigeon breeder’s Lung)
- Fever, Cough, Dyspnea hours after the exposure
- Resolves w/ removal fo the exposure
- Chronic exposure leads to Interstitial fibrosis
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Hypersensitivity Pneumonitis
10
Q
- HTN and High pressure w/ MAP > 25 mmHg at Rest, Normal = 10 - 14 mmHg
- A/w Atherosclerosis of the Pulmonary trunk
- Smooth muscle Hypertrophy of pulmonary arteries
- Intimal Fibrosis; Plexiform Lesions are seen w/ severe, long-standing disease
- Leads to RV Hypertrophy w/ Cor Pulmonale
- Exertional dyspnea or Right-sided Heart failure
- Subclassified as Primary or Secondary etiologies
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Pulmonary Hypertension
11
Q
- Classically seen in Young adult females
- Etiology is unknown; some Familial forms are related to Inactivating mutations of BMPR2 gene, normally funcitons to inhibit Vascular Smooth muscle proliferation
- Plexiform lesions in the Pulmonary arterioles w/out Hilan membranes
- Mutation leads to proliferation of Vascular smooth muscle → Poor prognosis
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Primary Pulmonary Hypertension
12
Q
- Cyanosis, RVH → Death or Cor Pulmonale
- Due to Hyposemia (COPD and interstitial lung disease)
- Mitral stenosis (↑ Resistance → ↑ pressure)
- Recurrent Thrombiemboli ( ↓ cross-sectional area of Pulmonary vascular bed)
- Autoimmune disease (SLE, Intimal Fibrosis)
- L2R shunt (↑ Shear stress → endothelial injury)
- Sleep apnea, Living at High altitude (hypoxic)
- or Increased Volume in the Pulmonary Circuit (e.g. congenital heart disease)
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Secondary Pulmonary Hypertension
13
Q
- Dmg to Alveolar-capillary interface (diffuse damage) → Leakage of Protein-rich fluid → Edema combines w/ necrotic epithelial cells to form Hyaline membranes (diffusely) in Alveoli
- Hypoxemia and Cyanosis w/ respiratory distress – Thickened diffusion barrier and collapse of air sacs (increased surface tension)
- ‘White-out’ on CXR
- 2nd to Sepsis, Infection, Shock, Trauma, Uremia, Aspiration, Pancreatitis, DIC, Amniotic fluid emboi, Hypersensitivity rxns, and Drugs
- Neutrophils induce protease- and free radical-mediated dmg of Type I and Type II pneumocytes, Coagulation cascade, O2 radicals
- Tx: underlying disease, positive end-expiratory pressure (PEEP)
- Interstitial fibrosis; damage and loss of Type H pneumocytes à scarring and fibrosis
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Acute Respiratory Distress Syndrome
14
Q
- Respiratory distress due to Inadequate Surfactant levels
- Surfactant made by Type II Pneumocytes; phosphatidylcholine (Lecithin) is the major component
- Lecithin:Spingomyelin < 1.5 in amniotic fliud is predictive of Neonatal RDS
- Surfactant def. → ↑ Surface tension in the lung, collapse of Alveolar air sacs after expansion
- Collapse of air sacs and formation of Hyaline membrane
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Neonatal respiratory distress syndrome
15
Q
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Prematurity – surfactant prod. stars at 28 weeks, adequate at 34
- Amniotic fluid Lecithin to Spingomyelin ratio is used to screen for lung maturity
- Phosphatidylcholine (Lecithin) levels increase as surfactant is produced; Sphingomyelin remains constant
- A ratio > 2 indicates adequate production
- C-section – due to lack of stress-induced steroids; ↓ Release of Fetal Glucocorticoids
- Maternal diabetes – ↑ Hyperglycemia; Babies pancrease makes insulin, surfactant decreases
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Neonatal Respiratory Distress Syndrome is A/w:
