Pleural Effusion and Other Pleural Disease

Question 1

Define pleural effusion.

Answer 1

Accumulation of an abnormal volume of fluid in the pleural space

Question 2

Describe the normal pleural fluid. (3)

How much is there?

Answer 2

Volume: <15ml
Clear, serous liquid
Contains few cells

Question 3

Define a small pleural effusion.

Define a large pleural effusion.

Answer 3

Small: <500ml

Large: 500+ml

Question 4

Describe the clinical features of pleural effusion.

What are the symptoms? (4)

What are the signs O/E? (3)

What would you see on chest imaging that strongly suggests pleural effusion? (1)

Answer 4

SYMPTOMS:
Asymptomatic
Breathlessness
Cough
Chest pain

SIGNS O/E:
Stony dull percussion
Reduced breath sounds
Reduced vocal resonance

IMAGING:
Blunting of costophrenic angles

Question 5

Describe the pathophysiology of pleural effusion. (3)

Answer 5

1. Balance between pleural fluid production and absorption is disturbed
2. This causes accumulation of fluid in the pleural space
3. This causes increased hydrostatic pressure
   a. This eventually leads to congestive heart failure

Question 6

What are the different mechanisms of pleural effusion pathogenesis?

i.e.

How can pleural effusion be caused? (6)

Answer 6

Increased hydrostatic pressure
Decreased osmotic pressure
Increased vascular permeability
Decreased lymphatic drainage
Increased intra-pleural negative pressure
Transdiaphragmatic passage of ascites from abdomen

Question 7

List 2 other types of fluid which might be found in a pleural effusion.

Answer 7

Blood (haemothorax)
Chyle (chylothorax)

This is RARE

Question 8

List 3 common conditions which can cause pleural effusion.

Answer 8

Congestive heart failure
Chronic liver disease
Pneumonia

Question 9

How would you investigate a pleural effusion? (5)

Answer 9

Clinical history
Clinical features
Pleural fluid analysis
Imaging
Pleural biopsy

Question 10

What 5 types of test will you do in pleural fluid analysis?

Answer 10

View on ultrasound
Colour of fluid
Biochemical tests
Microbiology
Cytology

Question 11

What types of biochemical test would you to classify type of pleural effusion? (5)

Answer 11

Protein levels
LDH
Glucose
Amylase
pH of fluid (if suspected infection)

Question 12

List 3 methods of pleural biopsy.

Answer 12

Under CT/US guidance
Abram’s needle biopsy
Thorascopy

Question 13

How is an Abram’s needle pleural biopsy carried out?

List 2 indications for this procedure.

Answer 13

METHOD:

1. Large needle inserted under US guidance
2. Inner sheath of needle takes biopsy

INDICATIONS:
Suspicion of pleural TB
Diffuse pleural involvement

Question 14

How is a thorascopy done? (2)

What are the advantages of this procedure? (3)

List 1 indication for this procedure.

Answer 14

METHOD:

1. Local anasthesia and mild sedation given
2. Parietal/visceral pleura and diaphragm viewed with a thorascope

ADVANTAGES:
Direct visualisation of pleura
Biopsy of abnormal areas
Therapeutic manoeuvres can be done (e.g. drainage, pleurodesis)

INDICATIONS:
Undiagnosed cytology negative pleural effusion

Question 15

What are the 2 types of pleural effusion?

Answer 15

Transudate

Exudate

Question 16

Which criteria are used to define an exudative pleural effusion?

Describe them. (3)

Answer 16

Light’s criteria:

High protein/LDH (2/3+ upper limit of normal serum values)
Pleural:serum protein ratio: 0.5+
Pleural:serum LDH ratio: 0.6+

(i.e. exudative = high protein)

Question 17

List 4 common causes of a transudate pleural effusion.

Answer 17

Heart failure
Hepatic cirrhosis
Nephrotic syndrome
Hypoalbuminaemia

Question 18

List 4 causes of an exudative pleural effusion.

Answer 18

Bacterial pneumonia
Malignancy
Mesothelioma
TB

Question 19

On a pleural biopsy, what are 3 abnormal histological features seen in mesothelioma?

Answer 19

Asbestos bodies (containing iron)
Mesothelial layer more than 1 cell thick
Mesothelial layer is not smooth/invades into chest wall

Question 20

Describe the criteria for diagnosing mesothelioma. (4)

Answer 20

Morphological malignant cells

Invasion of chest wall

Morphologically normal cells BUT with abnormal architecture

Morphology and architecture normal BUT with fibrosis

Question 21

How would you diagnose mesothelioma with immunocytochemistry tests? Consider:

a) Positive markers (2)
b) Negative markers (3)

Answer 21

POSITIVE:
Calretinin
CK 5/6

NEGATIVE:
TTF-1
BEREP-4
CEA (carcinoma embryonic antigen)

Question 22

What features of pleural effusion would you see on a chest x-ray? (3)

Answer 22

Blunting of costophrenic angles
Meniscus sign
Homogenous opacity

Question 23

Which 3 imaging modalities would you use for pleural effusion?

Answer 23

CXR
Ultrasound
CT

Question 24

Define asbestosis.

Answer 24

Diffuse interstitial fibrosis of the lung caused by asbestos dust

Question 25

Describe the clinical features of asbestosis.

What are the symptoms? (4)

What are the signs on imaging? (1)

Answer 25

SYMPTOMS:
Progressive SOB
Dry cough
Bibasalar inspiratory crackles
Finger clubbing

SIGNS ON IMAGING:
Lower zone fibrosis on CXR