3. Lung Pathology Flashcards
The ____ have C-shaped rings of cartilage with ____ glands
Trachea
Mucous Glands
The ____ have discontinuous cartilage plates and ____ glands
Bronchi
Mucous Glands
The ____ have NO Cartilage or Mucous Glands
Bronchioles
What are the two main types of Bronchioles and describe them
Terminal: <2 mm in diameter
Respiratory: Where Gas exchange takes place
The ___________ have a Flat Epithelium
No Glands
No Cilia
Alveolar Ducts
The __________ have
No Glands
No Cilia
Alveolar Sacs
What are the main Lung Diseases of Vascular Origin?
- Pulmonary Oedema
- Diffuse Alveolar Damage (Acute ARDS)
- Emboli/Infarction
- Pulmonary Hypertension
What can usually be seen in Pulmonary Oedema?
- Heavy Wet Lungs
- Alveolar Pink Granular Fluid with Haemosiderin-Laden Macrophages
- Brown induration
What can usually be seen in DAD (Diffuse Alveolar Damage)?
- Oedema fluid and Fibrinous Membranes lining alveoli
- –Oedema is caused by injury to Alveolar Capillary Endothelium
- –Also by Shock, Sepsis, Trauma - Can proceed to severe scarring
How are Emboli/Infarction caused and where can you find them?
- Pulmonary Artery Occlusion due to clots from Lower Deep Veins (Bedridden)
- Large Saddle Emboli are fatal
- Lodged at Bifurcation of Pulmonary Trunk - Smaller Emboli
- Lodged peripherally
- Wedge-shaped infarcts
For Emboli, where are Large saddle emboli usually lodged?
Bifurcation of Pulmonary Trunk
For Emboli, where are Small saddle emboli lodged?
Peripherally
How is Pulmonary Hypertension caused?
- When there is low Pulmonary circulatory resistance
- Increased Pulmonary Pressure is SECONDARY TO:
- COPD
- Left Valvular Heart Disease (Most common)
- Thromboemboli
What fatal conditions can Pulmonary Hypertension develop into?
Right Ventricular Hypertrophy and Failure or Chronic Cor Pulmonale?
What is Cor Pulmonale?
Condition causing the Right side of the heart to fail
- High BP of the Pulmonary Arteries
- High BP of the Right side of the heart
What can be observed in an Obstructive Pulmonary Disease?
- Low FEV1
- No decrease in TLC
- Narrowed Airway/Loss of Recoil
- Airway resistance
What can be observed in a Restrictive Pulmonary Disease?
- Low TLC and FEV1
- Decreased TLC
- Chest Wall/Interstitial Disorders/Infiltrative (Dust)
- Reduced Lung Parenchyma expansion
What are COPDs?
Group of diseases characterised by:
- Obstructed Air flow (Intermittent/Reversible/Irreversible)
- ANY level of the Respiratory Tract
Give FOUR examples of COPDs
- Bronchial Asthma
- Bronchiectasis (Airways widen and fill with mucus)
- Chronic Bronchitis
- Emphysema
What usually links both Chronic Bronchitis and Emphysema?
Both usually co-existent and usually via Smoking
What is the Clinical Definition of Chronic Bronchitis?
Productive cough for 3+ months in 2 consecutive years
What symptoms can you usually see in Chronic Bronchitis?
- Mucous Gland Hypertrophy
- Mucus Hypersecretion
- Hypoxia
- Hypercapnia
BLUE BLOATER
What is the Pathological Definition of Emphysema?
Permanent dilatation of the airways DISTAL to the Terminal Bronchiole
What symptoms can you usually see in Emphysema?
- Hyperventilation
- Normal Blood Gases
- Elastin is DESTROYED and there is less recoil
PINK PUFFERS
What types of Emphysema are there?
Centri-Acinar
Pan-Acinar
Distal Acinar (Paraseptal)
Irregular
What is Centriacinar Emphysema?
Affected Central/Proximal Parts of Respiratory Bronchioles
SMOKERS
What is Panacinar Emphysema?
Uniform dilation of Acini from Respiratory Bronchiole to the Alveoli
A1AT DEFICIENCY
What is Paraseptal Emphysema?
Peripheral along the Lung Margins
Adjacent to SCARRING/FIBROSIS/COLLAPSE
Predisposition to Spontaneous Pneumothorax in Young Adults
Which type of Emphysema predisposes to Spontaneous Pneumothorax in Young Adults?
Paraseptal
What is Irregular Emphysema?
Irregular involvement of Acini
SCARRING Patients
What is the pathogenesis of Emphysema?
Protease-Antiprotease Hypothesis:
- Imbalance of these two will DESTROY ELASTIN
What can lead to A1AT destruction?
- Congenital A1AT deficiency
- Smoking -> Free Radicals
- Smoking -> Elastase/PMN
What is Bronchial Asthma?
- Increased irritability of Bronchial Tree
2. Paroxysms (sudden attack) of Reversible Bronchospasm
What is the commonest cause of Bronchial Asthma?
Atopic
Caused by Type 1 HS to common allergens:
1. Pollen
2. House dust
What are the less common causes of Bronchial Asthma?
- Aspirin-induced
- Occupational Infection (Allergic Bronchopulmonary Aspergillosis)
Aspergillus fumigatus
What is Bronchiectasis?
- Perma dilation of the Bronchi/ioles with Wall Necrosis
2. Follows Obstruction/Viral Pneumonia
What symptoms usually come with Bronchiectasis?
- Saclike airways
- Foul pus/sputum
- Chronic Paroxysmal Cough due to posture change
What complications can Bronchiectasis lead to?
- Respiratory Failure (Insufficient O2 from Lungs to Blood)
- Atelectasis (Improper inflation of some segments)
- Cor Pulmonale
- Abscess (Pus)
- Fibrosis
- Clubbing
What are Restrictive Lung Diseases characterised by?
- Diffuse/Chronic Damage to:
- Pulmonary Interstitium
- Basement membranes
- Collagen
- Elastic Tissue
- Fibroblasts
- Leukocytes
What changes can be seen in RLDs?
- Physio: Less Oxygen diffusing capacity/volume/compliance in lungs
- Chest X-Ray: Diffuse infiltration by
- Small nodules
- Irregular lines
- Ground-Glass Shadows
What are the main causes of RLDs?
- Environmental Diseases (Occupational too): 25%
- Sarcoidosis: 20%
- Collagen Vascular Diseases: 10%
- Idiopathic Pulmonary Fibrosis: 15%
- Miscel
What is Occupational Lung Disease?
Diseases caused by inhaling dust/small particles
What are the Two Broad Mechanisms of Injury to the Lung?
- Scarring from Chronic Irritation (Inert substances/Pneumoconiosis from coal workers)
- Hypersensitivity (Dusts)
Give some examples for Occupational Lung Diseases
- Coal Workers:
Pneumoconiosis
Anthracosis
Progressive Massive Fibrosis - Silicon: Caplan’s Syndrome
- Asbestos: Lungs/Stomach/Colon
- Farmer’s Lung
Bagassosis (Bagasse Dust)
Byssinosis (Cotton/Hemp)
What is Sarcoidosis characterised by?
- Non-Caseating Granulomatous reaction in MANY tissues (Lungs 90% of the time)
- Found incidentally/present with respiratory symptoms
Can you treat Sarcoidosis?
Steroid therapy can be unpredictable
What type of cancers can be caused by Smoking?
- Lip
- Tongue
- Floor of Mouth
- Larynx
- Oesophagus
- Urinary Bladder
- Kidney
- Pancreas
What is the progression of cellular change in Smoking/Lung Cancer?
- Ciliated, Mucus-secreting, Pseudostratified, Columnar)
- Stratified Squamous
- Squamous DYSPLASIA
- Carcinoma
What are the different types of Lung Cancer?
- Squamous Cell Carcinoma
- Adenocarcinoma
- Small Cell Carcinoma
- Large Cell Carcinoma
- ETC
What is the relative percentage of individuals with Squamous Cell Carcinoma?
25-40%
What is the relative percentage of individuals with Adenocarcinoma?
25-40%
What is the relative percentage of individuals with Small Cell Carcinoma?
20-25%
What is the relative percentage of individuals with Large Cell Carcinoma?
10-15%
Which type of Carcinoma is known to be treated surgically?
NSCLC
Why is SCLC not treated surgically?
Widely disseminated at time of diagnosis
What do we use to treat SCLC then?
Chemotherapy
What are the mechanisms of Targeted therapy for NSCLCs?
- Block receptors with antibodies
- Block cell pathways with inhibitors
(Since Tumour cells express GFRs, we can block them to stop dividing) - Stop Angiogenesis by the tumour
- Encourage immune response to fight against the tumour cells
What are the main targeted receptors for NSCLCs?
EGFR
VEGR
MET
BRAF
What is EGFR?
Receptor usually detected by PCR or NGS
What is PD-1/PD-L1 interaction?
PD-1 Receptor on T cells
PD-L1 on Tumour Cells
This interaction can protect the cancer cell from immune destruction
If we block it, the T cells can destroy the tumour
PEMBROLIZUMAB
What are the Local clinical features of Lung Cancer?
Locally: Coughing/Haemoptysis/Pain
What are the General clinical features of Lung Cancer?
Weight Loss
Clubbing
Hypertrophic Pulmonary Osteoarthropathy
Why can Lung Cancer lead to PNS?
Paraneoplastic Syndromes are due to Ectopic Hormone production by tumour cells
- Hypercalcemia
- SIADH
What is the prognosis of Lung Cancer
Determined by Staging
5 Year survival usually
What is the clinical Definition of Asthma?
More than 1 of:
- Wheeze
- Breathlessness
- Chest tightness
- Cough
- EPISODIC
A. Variable Airflow Obstruction
B. Airway Hyper-responsiveness
C. Airway Inflammation
When considering Asthma, what should you consider?
- Episodic Symptoms
- Wheezing in Auscultation
- Diurnal Variability
- Atopy
- Absence of other symptoms
What drugs are given to treat Asthma as required?
Short Acting Bronchodilators
- Salbutamol
- Terbutaline
NOT RECOMMENDED ALONE
What drugs are considered 1st line regular maintenance for Asthma?
ICS
- Beclamethasone
- Budesonide
- Mometasone
- Fluticasone
What drugs are considered 2nd line regular maintenance for Asthma?
Long Acting Beta2 Agonists
- Salmeterol
- Formoterol
- Indacterol
- Vilanterol
What drugs are considered 3rd line regular maintenance for Asthma?
LTRA: Montelukast
Anticholinergics: Tiotropium
Theophyllines (Nasty side effects)
What drugs are considered 4th line regular maintenance for Asthma?
Anti-IgE therapy
Anti-IL5 Therapy
Other biological products
What drugs are considered 5th line regular maintenance for Asthma?
Oral Steroids
What is 33-92-CHEST?
Life-Threatening Asthma
- PEF < 33%
- Sats <92%
- Cyanosis
- Hypotension
- Exhaustion
- Silent Chest
- Tachy/Bradycardia