A diagnosis of mesothelioma is most often obtained with careful assessment of clinical and radiological findings in addition to a confirming tissue biopsy. (Learn about typical mesothelioma symptoms.) A review of the patient's medical history, including history of asbestos exposure is taken, followed by a complete physical examination, x-rays of the chest or abdomen, and lung function tests. A CT scan or MRI may also be done at this time. If any of these preliminary tests prove suspicious for mesothelioma; a biopsy is necessary to confirm this diagnosis

When a patient has symptoms suggesting malignant mesothelioma, a doctor starts with imaging techniques to confirm a diagnosis. X-rays and CT scans of the chest or abdomen are taken to identify any abnormalities, such as fluid collections, thickening of tissue, or growths, that may indicate underlying disease. Magnetic resonance images (MRI) or positron emission tomography (PET) images are taken to determine the extent of spread of a cancer; PET is most expensive but also the most accurate. Information from scans is used to plan appropriate treatment.