Week 1 - Lung Cancer/TB

Question 1

Lung Cancer

types

Answer 1

1. Small Cell LC
2. Non-Small Cell LC
   i. SQUAMOUS
   ii. ADENOCARCINOMA
3. Large Cell Carcinoma

stages 1) B/c hyperplasia & squam metaplasia 2) squa dysplasia 3) inv ca

1. SC (14%): chromosome deletion 17p(TP53) & Rb.
   high levels of BCL2.
2. i. SCC (20%): chromosome deletion 3p,9p & 17p.
   ii. AC (~40%): organic growth factors (VEGF, ALK, ROS).
3. LCC: undifferentiate malignant epithelial tumor. large nuclei, prominent nucleoli (Diag. of exl.).

Question 2

Bronchitis

Answer 2

Overproduction and hypersecretion of goblet cells:
- Hypersecretion: due o hypertrophy of submusocal glands in trachea (histamine & IL-13). increase g/c in small airways.

Inflammation:
- Cellular damage/irritants elicit both acute and chronic inflammatory response (->fibrosis of bronchi/bronchioles)

Bacteria:
haemophilus influenzae8
Strept pneuomia
Staph A.
Mycoplasma pneumoniae.

Question 3

Paraneoplastic Syndromes

Answer 3

Hormone like reaction due to cancer.
Include:
- Inappropriate ADH (->hyponatremia)
- Adrenocorticoropic hormone (ACTH) (->cushings)
- PTH (->hypercalcemia)
- Calcitonin (hypocalcemia)
- Gonadotropins (gynecomastia)
- Serotonin/Bradykinin (Carcinoid synrome (flushing, diarrohea, bronchocontriction, heart disease)

Question 4

Lambert-Eaton Syndrome

Answer 4

Autoimmune disorder caused by auto anti-bodies that block ACh release by inhibiting presynaptic Ca+2 channels.

Weak extremities.that improve w/ repetitive stimulation.

Question 5

Lung Cancer metastasizes

Answer 5

Small Cell/Adenocarincomas prefer brain.
Squamous cells prefer bone.

Question 6

Tuberculosis

Answer 6

Caused by Mycobacterium Tuberculosis.
Crhonic pulmonary disease. Spread via sputum from active infection.

Tuberculin skin test.
Vaccine = Bacillus Calmette-Guerin (BCG)

Steps of infection:
Entry; M. TB enters macrophages by phagocytosis mediated receptors (MBL, CR3).
Replication; Inhibition (via Ca+2 signals) of phagosom, allowing bacteria to replicate.
TH1 response; 3w post infection, TH1 activate macrophages turning them bactericidal (differentiation dependent on IL-12)
Killing; TH1 cells produce INF-gamma, whichs (stimulates phagosome, produces NO, defensins, Autophagy).
Grannulomatous: TH1 responses trigger grannulomatus (made of epithelioid histocytes(differentiated macrpohages)) formation and caseous necrosis.

Question 7

Brochiectasis

Answer 7

Widening of bronchi/bronchioles.

Chronic cough, increased mucus production

Question 8

6 respiratory symptoms

Answer 8

1. Cough
2. Wheeze
3. Dyspnoea
4. Sputum
5. Chest pain
6. Haemoptysis

2. occurs on expiration. contrast w/ STRIDOR (inhalation)

Question 9

Lung sound: Crackles

associations

Answer 9

Fluid filled alveoli.

Consolidation (pneumonia), fibrosis

Question 10

Lung sound: Wheeze

associations

Answer 10

Narrowing/inflamed bronchial tubes.

Question 11

Lung sound: absent

associations

Answer 11

Pneumothorax, effusion.

Question 12

Lung defence mechanisms

Answer 12

1. Anatomical
2. Mechanical
3. Immune

1. Nasal hairs/turbinates
2. Mucus, cilia, sneeze/cough
3. alveolar macrophages, IgA (upper airway), T cells

Alveoli contain IgG

Question 13

Lower respiratory tracct bacteria

Answer 13

Streptococcus pneumoniae.
Haemophilus influenzae.
Staph Aureus.
Klebsiella.

Legionella pneumophila.
Mycoplasma pneumoniae.

Colonize the upper tract but by passes defences to get lower.

Atypical; no cell wall

Question 14

Community Acquired Pneumonia vs Hospital Acquired

Answer 14

CAP = Strept pneumonia, influenza A.

HAP = Pseudomonas aeruginosa, E. coli, Klebsiella

HAP = in hospital >48hrs
HAP = leading cause of death from hospital acquired infection

Question 15

Legionella pneumophila

Answer 15

Gram Negative.
Causes Legionnaire’s Disease and Pontiac fever.
Resides in warm water (A/C).

Legionnaires = atypical pneumonia.

Question 16

Pancoast Tumor

Answer 16

Tumor at lung apex.

Question 17

Trousseau Sign of malignancy

Answer 17

migratory thrombosis.

Adenocarcinomas (% gliomas)

patho: associated w/ hypercoaguability.

Question 18

NSCLC immunotherapy

Answer 18

PD-1/PD-L1 inhibitors.

PD-1: Pembrolizumab, Nivolumab.
PD-L1: Atezolizumab, Durvalumab

Tumor cells use PD-L1 to inhibit PD-1 receptors on T-cells.