Case history

A 66 year old former shipyard worker presented to a medical admission department with increasing shortness of breath on exertion and worsening right sided chest pain over the previous month.

On questioning he admitted losing more than 7 kg in weight over the past two months. On examination, tar stained fingers and grade 3 finger clubbing are noted. Auscultation and percussion of the chest are suggestive of right sided pleural effusion.

Questions

1. In view of his previous occupation what further questions would you wish to ask this man?
   You proceed to a chest radiograph. While awaiting his chest radiograph, you review his past medical notes. You notice reference to "evidence of calcified pleural plaques" on a previous chest radiograph from 10 years earlier.
2. What causes pleural plaques and what other conditions are associated with exposure to this material?
3. What abnormalities are evidenced on this chest radiograph?
4. Why has this condition occurred now?
5. What special advice would you give this man and his family?

Answers

1. A detailed occupational history is required. What job did he do in the shipyard? What work occurred in his vicinity in the shipyard? Was he exposed to any materials, especially asbestos? What type of asbestos? Did he wear protective clothing or was it provided? Did he have other jobs during his lifetime--what were they? How long and when did he work there?
2. Pleural plaques are due to the exposure of an individual to asbestos. Asbestos is a mined mineral, comprising several naturally occurring fibrous silicates. Its versatility gives it a multitude of industrial uses, hence the term "the magic mineral." There are three main types: blue (crocidolite), white (chrysolite), and brown (amosite). White asbestos contains serpentine fibres while blue and brown are amphibole fibres.
3. There is a lobulated pleural based mass present on the right side. This is seen to encircle the right lung. There is little evidence of volume loss. Note also the calcified pleural plaque at the right apex.
4. The average lag interval (latent phase) between first exposure to asbestos and the development of malignant mesothelioma is 30 years (10-50 year interval). Hence, this man may have begun working with asbestos during his early 20s. The lag time between exposure and development of pleural plaques may also be of the order of 20 to 30 years. The incidence of mesothelioma is estimated to peak in 2025.¹
5. You should provide advice about government compensation. Industrial injuries disablement benefit is an entitlement to all sufferers. Trade union members may also wish to seek the help from their union in supporting a case for compensation against their employer.

For those unable to claim damages because the former employers have gone out of business or there is no realistic chance of pursuing a court action, compensation can be sought from the government under the Pneumoconiosis Etc (Workers' Compensation) Act 1979. Legal proceedings should start within three years of the condition being diagnosed.