Introduction
to Lung Disease
Dr Anjana Shakya
MD Pathology
Assistant Professor
CUHK SZ 2024
Email: anjanshakya@cuhk.edu.cn
Learning Outcomes
1. Define obstructive and restrictive lung diseases
2. Explain how obstructive and restrictive lung diseases affect lung compliance and
airway resistance
3. Classify lung cancer
4. Identify risk factors of lung cancer
5. Describe how the anatomical location of lung cancer influences clinical features,
diagnostic approaches, and treatment strategies.
Lung disease
1. Congenital anomalies
2. Pulmonary infections
3. Obstructive lung disease
4. Restrictive lung disease
5. Tumors of the lung
6. Pleural diseases
7. Disease of Vascular origin
8. Pulmonary edema
Cardinal Symptoms of Respiratory Disease
Upper respiratory
tract
• Nasal discharge
• Sore throat
• Hoarseness
Lower respiratory
tract
• Cough
• Sputum
• Hemoptysis
• Pleuritic chest pain : sharp, localized pain
• Shortness of breath
• Wheeze
Pathology of the LUNG
Obstructive lung disease
• increase in resistance to air flow caused by partial or complete
obstruction at any level
• difficulty in getting air out
Restrictive lung disease
• reduced expansion of lung parenchyma and decreased total
lung capacity
• difficulty in getting air in
Obstructive
Restrictive
COPD
Extrapulmonary disease
• Chronic bronchitis
• Emphysema
• Chest wall
• Muscles
• Pleura
Bronchial Asthma
Pulmonary disease
• > 200 disorders
Bronchiectasis
Depends on ability of
the lung to
Stretch
Recoil
Maintain airflow
Change in lung volume
per unit change in
pressure
Ability of lungs to return
to original shape after
being stretched
Ability to stretch
Ability to recoil
Facilitates lung inflation
during inhalation
Aids in lung emptying
during exhalation
High compliance
less recoil
Elastic recoil
Compliance
Compliance and Elastic recoil
The lung is both compliant and elastic
Compliant enough : to fill with air during inspiration
Elastic enough : to recoil and push air out during expiration
Airway resistance is inversely proportional
to radius of the airway
In healthy lungs, the airflow
usually does not encounter
significant resistance: air easily
enters and leaves the lungs
Wall
Lumen
Chronic Obstructive Pulmonary Disease (COPD)
Progressive airflow limitation due to airway and/or alveolar abnormalities
caused by exposure to noxious particles or gases (Smoking, pollutants)
Chronic
inflammation
Airway
narrowing
Chronic
bronchitis
Decreased
elastic recoil
Emphysema
Chronic Bronchitis: Cough with Sputum production
Squamous metaplasia
Hyperplasia and
hypertrophy of
the mucus glands
Smooth muscle hypertrophy
Fibrosis of the wall
Bronchoconstriction
Emphysema
Destruction of alveolar walls
Enlarged air spaces
Chronic Bronchitis
↓ Radius of the airway
↑ Resistance
↑ Effort in breathing
Air Trapped
Lungs hyperinflated
Barrel shaped chest
Emphysema
Radiographic appearances in the normal lung and in emphysema
1
Hypoxemia ↓O2
Hypercapnia ↑CO2
Both hypoxemia and hypercapnia stimulate the respiratory center
↑ RR
Clinical features of COPD
Why we see signs/symptoms of chronic bronchitis?
1. Mucus hypersecretion
Productive cough
2. Bronchoconstriction
Wheezing
Cyanosis
3. ↓ O2
Why we see signs/symptoms of emphysema?
1. Air trapping / hyperinflation
2. Air trapping / hyperinflation
3. Pink puffers/normal O2
Barrel Chest
Progressive dyspnoea
Over ventilate
Restrictive pulmonary disease
Definition
• Group of disorder characterized by reduced expansion of the lung and
reduction in total lung capacity
• Difficulty in getting the air in
• Caused by:
• Intrinsic : Pulmonary parenchyma diseases
• Extrinsic : Extrapulmonary diseases
Interstitial Lung Diseases
Diffuse parenchymal lung disease
• Large (>200) Diverse group of disorders
• Characterized by
• Diffuse chronic inflammation of the pulmonary parenchyma
• Collagen deposition in the interstitium, leading to pulmonary fibrosis
• Progressive and irreversible
• Clinical – dyspnea, dry cough (reduced compliance) and hypoxia(abnormal ventilation/perfusion)
• Radiographic – Bilateral, patchy fibrosis/scarring seen as small nodular opacities and irregular lines
Pathogenesis of ILD
Known
Repeated stimulus
Unknown – idiopathic
Injury to alveolar epithelium
Prolonged exposure
Genetics factors
Abnormal wound healing
↑Proliferation of fibroblast and ECM production
↑ stiffness
↓compliance
↓ Gas exchange
Fibrosis in the interstitium
Stiffening of lung tissue reduces its ability to expand
(↓ compliance) leading to reduced lung volume
Thickening of alveolar septae
Impaired Gas Exchange
Interstitial Lung Diseases
Fibrosis
Fibrosis
Idiopathic Pulmonary Fibrosis
Chest X ray : Opacities
Chest Ct scan : Honeycombing
Summary
Key Concepts
• Lung Compliance
• Ability of lungs to stretch and
expand
• Airway Resistance
• Opposition to airflow during
breathing
• Elastic Recoil
• Ability of lungs to return to
original shape
Lung Disease
• Obstructive: Difficulty breathing out
• COPD: Chronic inflammation due to smoke
• Chronic bronchitis
• narrowing in the airway ↑ airway resistance
• Emphysema
• destruction of the alveoli wall loss of elastic recoil
• Restrictive: Difficulty breathing in
• Extrapulmonary : chest wall abnormalities
• ↓ chest expansion
• Interstitial Lung Disease : abnormal fibrosis in interstitium
• ↓ compliance and impaired gas exchange
What is LUNG/bronchogenic CARCINOMA?
• Malignancies that originate in the airways or pulmonary parenchyma.
• From the respiratory epithelium (bronchi, bronchioles, alveoli)
1.
2.
3.
4.
Causes/risk factors
Smoking
Genetics/Family history
Occupational
Environmental/air pollution
Types of Lung cancer
Small cell cancer
Squamous cell cancer
Non Small cell cancer
Adenocarcinoma
Large cell cancer
Cell of origin
Lung Cancer – Clinical features
1. Local symptoms
2. Local invasion/regional spread
3. Constitutional symptoms
4. Distant Metastasis
5. Paraneoplastic symptoms
Lung Cancer Location and Symptoms
Obstructive Symptoms
Cough
Hemoptysis
Wheezing
Recurrent pneumonia
Asymptomatic
Found incidentally
Pleuritic chest pain
Central
Local invasion/regional spread
Tumour compresses/involves the mediastinal structures
1. Oesophagus: dysphagia
2. Recurrent laryngeal nerve: hoarseness
3. Superior Vena Cava : facial and upper limb swelling
4. Pancoast tumour: Pancoast syndrome and Horner syndrome
5. Chest wall invasion – chest pain – peripheral tumour
6. Phrenic nerve: difficulty breathing, diaphragmatic paralysis
Pancoast Tumours
Tumour growth in apical region of lungs with unique set of symptoms
1. Pancoast syndrome
• the brachial plexus, cervical
paravertebral sympathetic
nervous system, and stellate
ganglion
2. Horner syndrome
• Sympathetic ganglion
Diagnosis
Imaging Techniques:
• Chest X-ray: initial test, identify lung masses, nodules, and other suspicious lesions.
• Computed Tomography (CT): detect lung nodules and assess their size, shape, and
location and aid in staging
• Positron Emission Tomography (PET): staging and detecting distant metastases.
Pathological Examination:
• Fine Needle Aspiration (FNA): provide a preliminary diagnosis and help determine the
nature of the lesion (benign vs. malignant).
• Bronchoscopy: bronchial washing, brushing, and biopsy, can aid in diagnosing lung
conditions
• Biopsy: surgical removal or sampling of tissue from a lung mass, provides definitive
histopathological information, including tumor type, differentiation, and genetic
alterations, facilitating accurate diagnosis and informing treatment decisions.
Staging of lung cancer
Assess the extent of the disease, predict prognosis, and guide treatment
Tumor (T) Stage
• describes the size and extent of the primary tumor
including involvement of nearby structures and tissues
Node (N) Stage
• spread to the regional lymph nodes
Metastasis (M) Stage
• presence or absence of distant metastases
Staging of lung cancer
Combination of the T, N, and M
or adjacent structures
.
Treatment
• Depends on type, stage & location
• Options:
• Surgery
• Chemotherapy
• Radiotherapy
• Targeted therapy
• Non-small cell : All
• Small cell : Chemo & radiotherapy
Pleural Mesothelioma
Cancer of mesothelial cells, arising in the parietal or visceral pleura
• Exposure to asbestos
• Long Latent period 25 to 40 years
• Presents with locally advanced disease
• Metastasis rare
• Poor prognosis
Symptoms / Signs
1. Breathlessness
2. Pleural effusion or pleural thickening
3. Chest pain is typically dull, diffuse, progressive.
4. Palpable chest wall mass.
Thank You
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