Pleural Calcification On Chest X ray

A 45 years male patient came to radiology department for X-ray chest with history of cough and expectoration of several months duration.

The X ray is shown below:

Chest X-ray (in the above picture) shows a large plaque of calcification covering the lateral and anterior part of left lung. There is crowding of overlying ribs.
Calcified pleural plaques have a characteristic rolled edge along its margin
Left upper lobe shows fibrotic lesions with bronchiectatic change and calcific spots are also seen.

Explanation:
Magnified view (shown below) shows that pleural calcification plaques have a characteristic rolled edge along its margin. (marked by arrows)

In general, pleural calcification is sequelae of hemothorax, empyema, tuberculosis or asbestos exposure.

Hemothorax is usually confirmed by a history of significant chest trauma.
There may be associated healed rib fractures. Although pulmonary contusion may have accompanied the acute episodes, contusion usually resolves without significant residual effect. Associated parenchymal scarring thus favors a diagnosis other than previous hemothorax.

Clinical Discussion:
Chronic empyema is a more common cause of pleural calcification. Recent CT studies indicate that chronic empyemas may calcify around their periphery while retaining collections of fluid for years. Occasionally, calcified pleural thickening from empyema does assume unusual or bizarre configurations and may be very extensive. It must be remembered that the interlobar fissures are part of the pleural space and may, therefore, be involved by an empyema.

In tuberculosis, pleural reaction is most commonly apical and asymmetric. Associated apical parenchymal scarring, cavities, or even multiple calcified granulomas are virtually diagnostic of tuberculosis.

Asbestos exposure is a common cause of pleural calcifications measuring less than 3–4 cm. The pleural calcifications resulting from asbestos exposure most commonly affect the domes of the diaphragmatic pleura. They may be extensive and bilateral but are often asymmetric.

High Resolution CT has shown to be the most sensitive means for detecting minimal pleural changes from asbestos exposure. Pleural calcification is not seen in all cases of asbestos exposure, but can lead to one of the most specific appearances in chest radiology.

Calcified pleural plaques seen en face has a characteristic rolled edge along their margins, denser than in the central portion of the plaque.