Clinical Respiratory

Question 1

Kartagener

Answer 1

• MT (25 nm): contains 13 circularly arranged proteins called alpha & beta tubulins
• dynamic equilibrium with cytoplasmic pool of alpha & beta tubulins such that polymerization (plus) and a depolymerization (minus) ends are present on each MT
• Assoc. with MAPs- MT association proteins- Kinesin, Dynein, Dynamin
• Impairment of mucociliary clearance

Question 2

Laryngeal Carcinoma

Answer 2

• squamous cell carcinoma
• most commonly found in true vocal cords
• Light microscopy shows:
  
  • Keratin pearls: keratinization
  • nl epithelium
  • Dysplastic epithelium: immature cells (large nuclei), mitotic figures
• smoking is a huge risk factor; alcohol may also exacerbate

Question 3

Hyaline membrane disease/Neonatal respiratory distress syndrome

Answer 3

• decreased alveolar surfactant leading Atelectasis
• Hypoxemia + respiratory acidosis
• predisposing feature: immaturity of lungs
  
  • prematurity
• plasma leak into alveoli leading to Fibrin + Necrotic cells (hyaline membrane)
  
  • dead cells & macrophage

Question 4

Bronchial asthma

Answer 4

• chronic inflammatory disorder of airways
• hypersensitivity
• Hallmarks
  
  • increased airway responsiveness, i.e. incresed airway sensitivity to allergens
  • episodic bronchoconstriction
  • inflammation of bronchial walls
  • increased mucous secretion
  • increased cells in Lamina Propria
  • Increased Mast Cells, Lymphocytes, Eosionphils since infection is chronic
• Light microscopy shows:
  
  • airway remodelling
  • hypertrophy of smooth muscle
  • hyperplasia of mucous glands
  • marked infiltration by eosinophils
  • bronchial lumen obstructed by mucous
• Rx:
  
  • 1st line: bronchodilators: beta2-agonists (Salbutanol)
  • 2nd line: cort

Question 5

COPD

Answer 5

• collective name given to Emphysema & Chronic Bronchitis (no specific changes)
• characterized by an increase in resistance to airflow due to partial or complete obstruction
• common extrinsic trigger: cigarette smoking

Question 6

Emphysema

Answer 6

• characterized by irreversible enlargement of airspaces distal to terminal bronchioles & destruction of their walls without fibrosis (but can progress to pulm. fibrosis)
• Pathogenesis:
  
  • Protease/anti-protease imbalance: emphysema is more common people with alpha-1 antitrypsin deficiency
  • entry of neutrophils from the capillaries into alveolar spaces
  • increased release of proteases from leucocytes
  • unchecked destruction of elastic tissue due to deficiency of anti-trypsin
• Light microscopy shows:
  
  • dilatation of alveoli
  • destruction of alveolar walls
  • subpleural bullae (blebs): rupture produces pneumothorax

Question 7

Chronic Bronchitis

Answer 7

• persistent cough with sputum production for at least 3 months, in at least 2 consecutive years, in absence of any other identifiable cause
• initiating factor: chronic irritation ex. tobacco smoke
• affects both large & small airways
• Light microscopy shows:
  
  • infiltration of submucosa by chronic inflammatory cells
  • hypertrophy of smooth muscle
  • hyperplasia of mucous glands
• DDx with asthma -> check hypersensitivity

Question 8

Lung Carcinoma

Answer 8

• one of the most frequently dx cancers in world
• most well known lung carcinogen - tobacco smoke
• endless morphological types:
  
  • squamous cell
  • small cell
  • adenocarcinoma
• precursor lesions for squamous cell carcinoma
  
  • starts with squamous metaplasia or dysplasia in tracheobronchial tree -> carcinoma in situ
  • pseudostratified squamous to stratified squamous
  • Goblet cell hyperplasia
  • basal cell hyperplasia
  • squamous metaplasia: large immature cells, disordered epithelium, nuclear hyperchromasia
  • carcinoma in situ
  • same features as frank carcinoma apart from an intact basement membrane
  • squamous cell carcinoma
  • large eosinophilic cells with central whorling (keratinization)
  • dyskeratosis: keratin formation is commonly seen

Question 9

Cystic Fibrosis (mucoviscidosis)

Answer 9

• dehydrated viscous mucus