Diseases of the Pleura

JB

What is the pleura? A closed sac of serous membrane which contains

serous fluid.

There is a visceral pleura which covers each lobe and

passes into the separating fissure.

There is a parietal pleura adherent to the chest wall

and diaphragm. It is continuous with the visceral pleura

around the edges of the hilum.

The pleural cavity

only with a thin film of serous fluid.

http://www.merck.com/media/mmhe2/figures/MMHE_04_052_01_eps.gif

Pleural disease

1. Focal plaque formation

2. Calcification

3. Diffuse thickening

4. Effusion

Pleural effusion

Excess fluid in the pleural cavity.

This fluid can be:

Serous fluid (hydrothorax)

Blood (haemothorax)

Chyle (chylothorax)

Pus (empyema)

Can be transudate or exudate

Causes

Transudative: LVF and cirrohsis of the liver

Exudative; bacterial pneumonia, cancer and PE

Radiological appearances

No air bronchograms (as would be present with consolidation)

Concave upper boarder (meniscus)

No mediastinal shift

Consider lateral view

Terminates around midcardiac border

Can be loculated (smooth, homogenous, elliptical opacity)

Loculated pleural fluid in left major

fissure

Pleural Plaques

Circumscribed areas of pleural thickening,

located on parietal pleura.

3-10mm in thickness

1-5cm in length

Typically linked to asbestos exposure

Smooth or nodular

Calcified and non calcified

Radiological appearance

Isolated pleural thickening

Easier to identify on the periphery

Does it follow interpulmonary structures? If so,

it is probably not pleural

Commonly found around anterior border of ribs

Bilateral and in mid and axially regions

Calcification around diaphragm

Patchy appearance

Consider previous radiographs, slow growing!

Other causes of calcification

Silicosis

Treated lymphoma

Sarcoidosis

Pneumoconiosis

The above can all give the appearance of

Egg Shell Calcification of Lymph

Nodes

Occurs in 5% of patients.

Also seen in silicosis,

pneumoconiosis &

lymphoma following

radiotherapy.

Calcification appears about 6

years after onset of the

disease & is associated with

advanced pulmonary disease

& steroid therapy.

(Chapman, Nakielny, 2003)

Source:http://pathhsw5m54.ucsf.edu/cts/unknown5/eggshell.html

calcification of hilar

lymph nodes

Industrial lung disease

They can give similar nodular patterns but do

not give the same calcified appearance of

asbestos related pleural disease

Chronic lung disease will be discussed elsewhere

Diffuse pleural thickening

Generally uniform increase in pleural width

Can be calcified but not extensively

Rarely involves the mediastinum

Diagnosed predominantly by CT

Mesothelioma

Malignant neoplasm of the mesothelial cells of

the pleura

Asbestos exposure

Can be difficult to differentiate from metastatic

disease

85-90% male

Radiological appearance

Unilateral lobulated pleural thickening encasing

the entire lung

Occasionally, can be seen as multiple masses

Unilateral effusion

Loss of lung volume on affected side

No meniscus

Differential: metastatic adenocarcinoma,

lymphoma

Look for presence of pleural plaques