This test is rarely necessary in the diagnosis of mesothelioma. For the test, an instrument called a mediastinoscope is used to examine the space in the centre of your chest (the mediastinum). The space contains your heart, the main blood vessels and lymph glands. You have to have a general anaesthetic for this test. In some cases it may be done as a day case, for others, it may require a short stay in hospital of one or two nights maximum.

For the test, the doctor makes a small cut at the base of your neck, and passes a small viewing tube through the cut, into the chest. A sample of tissue may be taken for examination under a microscope.