10. Pleural disease

Question 1

Types of pleural disease

Answer 1

1. Pleural Effusion
2. Pneumothorax
3. Pleuritis
4. Mesothelioma

Question 2

Definition of pleural effusion

Answer 2

Can be classified as non-inflammatory effusions (hydrothorax, haemothorax, chylothorax) & inflammatory effusions (pyothorax)

Question 3

Hydrothorax

Answer 3

1. Fluid accumulation in pleural cavity
2. Causes:
   - Transudate: due to cardiac, renal or liver failure, or obstruction of lymphatic drainage
   - Exudate: due to inflammation or tumour

Question 4

Haemothroax

Answer 4

1. Blood accumulation in the pleural cavity

2. Due to trauma or surgery

Question 5

Chylothorax

Answer 5

1. Chyle (lymph fluid) accumulation in the pleural cavity

2. Due to leakage from the thoracic duct

Question 6

Pyothorax

Answer 6

1. Pus accumulation in the pleural cavity
2. Causes:
   - Contiguous spread from intrapulmonary infection
   - Hematogenous spread from distant infection
   - Spread through diaphragm (e.g. liver abscess affecting right pleura)

Question 7

Definition of pneumothorax

Answer 7

Air or gas in the pleural cavities

Question 8

Causes of pneumothorax

Answer 8

1. Spontaneous
   - Rupture of congenital bleb
   - Rupture of emphysematous bulla
2. Traumatic
   - Rib fractures
   - Penetrating chest injuries
3. Iatrogenic
   - Lung biopsy
   - Positive pressure ventilation

Question 9

Tension pneumothorax

Answer 9

1. Special case in which defect in chest wall acts as a one-way valve permitting the entrance of air during
   inspiration but does not permit escape during expiration → collapse of the ipsilateral lung
2. Increases pressure which compresses mediastinal
   structures & contralateral lung

Question 10

Definition of pleuritis

Answer 10

Inflammation of the pleura, also known as pleurisy

Question 11

Causes of pleuritis

Answer 11

1. Infections
2. Complication of pneumonia
3. Connective tissue diseases
   - Rheumatoid arthritis
   - Rheumatic fever
   - Systemic lupus erythematosus

Question 12

Pathological effects & complications of pleuritis

Answer 12

Fibrosis of pleural cavity

Question 13

Definition of mesothelioma

Answer 13

Primary malignant tumour of the mesothelium-lined pleura; note that primary tumours of the pleura (mesothelioma or others like fibromas) are very rare, and that metastatic tumours to the pleura are more common

Question 14

Risk factors for mesothelioma

Answer 14

Prior exposure to asbestos (may have a latent period of up to 50 years before development of tumour)

Question 15

Gross appearance of mesothelioma

Answer 15

1. Diffuse tumour which spreads widely in pleural space

2. Thick sheets of white tumour encasing lung & mediastinal structures

Question 16

Histological appearance of mesothelioma

Answer 16

Usually a biphasic mixed pattern composed of:

1. Spindle cell (sarcomatoid component, resembles fibrosarcoma)
2. Glandular structures (epithelial component, resembles adenocarcinoma)