Lung

1
Lung
Type I pneumocyte
Type I pneumocyte
Alveolar space
Capillary lumen
Type II pneumocyte
Endothelium
2
Pneumonia

• Pathology
• Alveolar
• Bronchopneumonia (Streptococcus pneumoniae,
  Haemophilus influenza, Staphylococcus aureus)
• Lobar (Streptococcus pneumoniae)
• Interstitial (Influenza virus, Mycoplasma
  pneumoniae)
• Pathogenesis
• Inhalation of air droplets
• Aspiration of infected secretions or objects
• Hematogenous spread

3
Pulmonary infectionsPredisposing factors

• Decreased cough reflex
• Injury to cilia
• Decreased function of alveolar macrophages
• Edema or congestion
• Retention of secretions

4
Lung abscess

• Localized suppurative necrosis
• Organisms commonly cultured
• Staphylococci
• Streptococci
• Gram-negative
• Anaerobes
• Frequent mixed infections
• Pathogenesis
• Aspiration
• Pneumonia
• Septic emboli
• Tumors
• Direct infection

5
Pulmonary tuberculosis

• Caused by Mycobacterium tuberculosis.
• Transmitted through inhalation of infected
  droplets
• Primary
• Single granuloma within parenchyma and hilar
  lymph nodes (Ghon complex).
• Infection does not progress (most common).
• Progressive primary pneumonia
• Miliary dissemination (blood stream).

6
Pulmonary tuberculosis

• Secondary
• Infection (mostly through reactivation) in a
  previously sensitized individual.
• Pathology
• Cavitary fibrocaseous lesions
• Bronchopneumonia
• Miliary TB

Fibrocaseous
Miliary
Granuloma
Mycobacterium
7
Opportunistic pneumonias

• Infections that affect immunosuppressed patients
• Associated disorders
• AIDS
• Iatrogenic
• Cancer patients
• Transplant recipients

Aspergillus
Pneumocystis carinii
Cytomegalovirus
8
Chronic obstructive pulmonary disease
(COPD)Chronic bronchitis

• Definition
• Persistent cough with sputum production for
• at least 3 months,
• in at least 2 consecutive years.
• Pathology
• Inflammation of airways
• Hyperplasia of mucous producing cells
• Squamous metaplasia
• Injury to cilia

9
Chronic obstructive pulmonary disease
(COPD)Emphysema

• Destructive enlargement of airspaces distal to
  terminal bronchioles
• Two main types
• Centriacinar
• Destruction of central portion with sparing of
  distal airways
• Upper lobes gt lower
• Cause smoking
• Panacinar
• Unform injury
• Lower lobes gt upper
• Cause alpha-1-antitrypsin deficiency

Alpha-1-AT
Neutrophils
10
Bronchiectasis

• Dilatation of bronchi and bronchioles secondary
  to chronic inflammation
• Associated conditions
• Obstruction
• Cystic fibrosis
• Immotile cilia syndromes
• Necrotizing pneumonia

11
Bronchial Asthma

• Chronic inflammatory disorder of the airways
  resulting in contraction of bronchial muscle
• Types
• Extrinsic (atopic, allergic).
• Allergens food, pollen, dust, etc.
• Intrinsic (non-atopic)
• Initiated by infections, drugs, pollutants,
  chemical irritants

ATOPIC ASTHMA
12
Atelectasis

• Collapse or incomplete expansion of part or all
  of the lung
• Types
• Resorption (obstruction of airway).
• Compressive (pleural effusion or pneumothorax)

13
Pulmonary edema
Oncotic pressure
Hydrostatic pressure
Normal
Hydrostatic pressure
Oncotic pressure
Causes - Heart failure - Mitral stenosis
Oncotic pressure
Hydrostatic pressure
Causes - Nephrotic syndrome - Liver
diseases
Causes - Infections - Aspiration - Drugs
- Radiation
Microvascular injury
14
Diffuse alveolar damage

• Acute respiratory distress syndrome (respiratory
  failure and arterial hypoxemia refractory to O2
  therapy).
• Basic lesions injury to pneumocytes and
  endothelial cells by
• Oxygen-derived free radicals
• Activated neutrophils and macrophages
• Loss of surfactant.
• Etiology
• Infections (viral)
• Gas inhalation or liquid aspiration
• Drugs, chemical, radiation
• Hypotension, sepsis, trauma
• Pathology
• Acute (exudative) stage
• Proliferative or organizing stage

Exudative stage
Proliferative stage
15
Pulmonary embolism

• Most emboli arise in veins from the legs
• Large emboli (10) are a cause of sudden death
• Small emboli (70) may be
• Clinically silent
• Cause infarctions (in patients with heart
  failure).
• Cause hemoptysis
• Medium sized emboli (20) generally cause
  infarctions.

Infarct
16
Pulmonary hypertension
Expected luminal opening in normal individual

• Secondary (most common)
• Chronic obstructive pulmonary disease
• Chronic interstitial pulmonary disorders
• Chronic heart failure
• Recurrent pulmonary emboli
• Primary (idiopathic)

Plexiform changes
17
Hypersensitivity pneumonitis

• Immunologically mediated disorder affecting
  airways and interstitium.

18
Usual interstitial pneumonia / idiopathic
pulmonary fibrosis

• Progressive fibrosing disorder of of unknown
  cause
• Adults 30 to 50 y/o
• Respiratory and heart failure (cor pulmonale) 5
  y

19
Pneumoconioses

• Disorders caused by inhalation of inorganic
  elements, primarily metals.
• Injury is determined by
• Length of exposure
• Physicochemical characteristics
• Host factors
• Carbon dust - Coal workers pneumoconiosis
• Anthracosis
• Simple coal workers pneumoconiosis
• Progressive massive fibrosis
• Silicosis
• Silicotic nodules
• Asbestos
• Asbestosis (pulmonary fibrosis)
• Pleural disease (fibrous plaques, mesothelioma).

20
Carcinoma of the Lung

• 6.5 of all deaths
• 1 cause of cancer deaths in males females
• 31 of male cancer deaths in 2001
• 90,367 deaths
• 25 of female cancer deaths
• 65,506 deaths

21
Lung cancer
Lung cancer in females
Lung cancer in males
22
Cancer Deaths estimated for 2004
23
Smoking-related diseases
24
Annual death rate for lung cancer
25
Causes of Lung Cancer

• 85-95 smoking
• 1 asbestos smoking (estimate)
• Rare arsenic, chromium, mustard gas, nickel,
  vinyl chloride, bis (chloromethyl) ether
• Speculation
• 0.3-3 passive smoking
• 3-14 radon

26
(No Transcript)
27
Classification of Lung Carcinoma (Major Types)

• Squamous cell carcinoma 35
• Adenocarcinoma 30
• Small cell carcinoma 25
• Large cell carcinoma 10

28
Squamous cell carcinoma

• Frequency 35
• Smoking X 25 (increased risk)
• Males gt females
• Survival (5 years) 15 - 20
• Arises in bronchial squamous metaplasia
• Centrally located
• May cavitate

29
(No Transcript)
30
Adenocarcinoma

• Frequency 30
• Smoking X 3 (increased risk)
• Males lt females
• Survival (5 years) 15 - 20
• Peripheral

31
Bronchioloalveolar carcinoma

• Frequency 2
• Smoking yes
• Males females
• Survival (5 years) 25 a 40 .
• Presentation
• Single or multiple tumor nodules
• Miliary tumor
• Pneumonic form

32
Small cell carcinoma

• Frequency 25
• Smoking 95 of patients
• Males gtgt females
• Survival (5 years) 1 - 5 .

33
(No Transcript)
34
Large Cell Carcinoma

• Frequency 10
• Gross
• Peripheral lesion
• Microscopic
• Wastebasket group of tumors that do not fit the
  criteria of a squamous cell carcinoma,
  adenocarcinoma, or small cell carcinoma
• Prognosis
• Similar to adenocarcinoma

35
(No Transcript)
36
(No Transcript)
37
(No Transcript)
38
(No Transcript)
39
Mesothelioma

• Mesothelioma
• Malignant tumor of mesothelial cells
• Highly malignant neoplasm with short survival
• Most patients (70) have an asbestos exposure
  history
• Asbestos exposure also increases the risk of
  pulmonary cancer
• Smoking is not related to mesothelioma