Diagnosis of Mesothelioma cancer is very difficult in many cases, because its symptoms can be associated with other diseases too. Hence patient's medical history is quite important to know, since if there was an exposure to asbestos from the sick person, the risk factors for developing Mesothelioma are greater.

The doctor will order you a physical examination, including chest and abdomen x-rays, and lung function tests. A computerized tomography (CT) or a computerized axial tomography (CAT) scan may be useful, along with a magnetic resonance imaging (MRI).

The CT scan allows a computer x-rays machine to create a series of detailed pictures of inner body areas. The MRI allows to obtain detailed images of areas inside the body through a powerful magnet linked to a computer.

The way to confirm a Mesothelioma diagnosis is a biopsy, in which an oncologist or a doctor specialized in diagnosing and treating cancer pathologies takes a sample of tissue from the patient to examine it under a microscope.

The biopsy may be performed in various ways. In a thoracoscopy the name of the biopsy if the cancer is in the chest the doctor makes a small cut through the patient's chest and introduce a tube called thoracoscope to look inside and take tissue samples.

In a peritoneoscopy if the cancer is in the abdomen the doctor makes the same procedure but in the patient's abdominal cavity to obtain tissue for examination.

The stage of the disease is important to know if cancer is metastasized to other parts of the body, and to apply the best treatment for the patient.

The disease will be 'localized' if the cancer is found only on the surface of the membrane, but it will be 'advanced' if it has spread to other parts of the body, such as lungs, abdominal organs, chest wall, lymph nodes.