Mesothelioma Diagnosis A doctor can identify the condition by physical exam, imaging tests and lab tests. Doctors can also perform biopsy procedures to remove tissue and study it under microscope. A chest X-ray or CT scan is used to guide the needle through the lung's lining. The procedure is aninvasive and is at risk of revealing false-negative results. Diagnosis It can take a while to determine mesothelioma since it is a rare form of cancer. Your doctor will begin by taking a medical history and conducting a physical exam to look for sympto