The most deadly form of asbestosis disease, the incurable malignant cancer, mesothelioma, is almost always diagnosed in the mesothelium, i.e. the membrane lining many of the body’s organs and cavities. However, it is not unknown for the fatal disease to spread to a different and unexpected area of the body after treatment.

The two most typical areas are those lining the cavity of the lungs (pleural mesothelioma) and surrounding the abdomen (peritoneal mesothelioma). On rare occasions, tumours have been known to be found in the membrane enclosing the heart (pericardial mesothelioma) and in the fluid-filled sac surrounding the testicles (testicular mesothelioma).

The long latency period of between 15 to 50 years from initial exposure and the inhaling of the deadly fibres to the emergence of either mesothelioma or asbestosis symptoms almost always means that malignant mesothelioma will be extremely difficult to treat, especially if diagnosed in the latter stages of tumour spread.

In addition, mesothelioma is not a centralised tumour mass and tends to spread along nerves, blood vessels, and tissue surfaces. Confusing close similarities with other types of respiratory or cancer diseases and a history of cigarette smoking can also cause delays in correct diagnosis and treatments.

Despite recent improvements, patient survival rates are seldom beyond 4 to 12 months. Many cases are reported where it is usually the surviving spouse or a close relative who pursues a mesothelioma claim within the specified three year period.

New case studies show the considerable additional challenges still facing doctors and surgeons in successfully handling the disease. There have been the re-appearance of tumours in different body locations, such as the colon and pelvic walls, after an original course of combined surgery, radiotherapy and chemotherapy to treat cases of malignant pleural and peritoneal mesothelioma.

Also, 14 cases of malignant pleural mesothelioma have been recorded appearing in the mouth, and in eight cases, on the tongue. In over 60 per cent of cases, mesothelioma reaching the oral cavity was epithelioid – the most common cell type, which are shaped like cubes, originally to be found in the mesothelium.

The findings also throw out a warning that even though there are no recorded cases of mesothelioma spreading to the breast, it is possible for breast cancer to spread to the pleural cavity where the genetic similarities between breast and mesothelioma tumours could lead to a misdiagnosis of mesothelioma.

According to the World Health Organization (WHO), 6,000 deaths are recorded annually from mesothelioma, worldwide, two thirds occurring after the year 2000.