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.