It is often difficult to diagnose Mesothelioma because it shows signs and symptoms that are very similar to different lung diseases and other medical conditions. A formal diagnosis is carried on by reviewing the patient’s medical history. This is the first step of the diagnosis.

The history of asbestos exposure might increase a patient’s chances of being diagnosed with Mesothelioma and his medical history would reveal that. The medical history will help the doctor determine if there are any chances of Mesothelioma in the patient’s body.

After reviewing medical history, a physical examination is carried out. Next follows a chest X-ray. Other tests related to lung function are performed to carry on the elimination process of other possibility of other lung diseases.

The X-ray plays vital role in detecting Mesothelioma. It reveals if the pleural has thickened which is a common occurrence in people exposed with asbestos. The thickened pleural will increase the suspicion of Mesothelioma. To be certain of the presence or absence of Mesothelioma, next step is a CT, CAT or MRI scan. It is quite a necessary step to take because even after the diagnoses that suggest the presence of cancer has been made, Mesothelioma looks similar to other types of cancers so in-depth examination is a must.

If any of the scan shows the presence of significance amounts of liquid in the cells, they may be detected by performing cytopathology. This is done by using a thin hollow syringe that is inserted to get infected cells out to examine them under the microscope. In this procedure, the syringe will be used to get an amount of fluid out so it can be examined for the infection of Mesothelioma.

In case of pleural fluid, this procedure is performed by thoracentesis or inserting a chest tube. Ascites is determined by using ascetic drain or paracentesis to draw fluid out of the peritoneal cavity in the abdomen. To perform the test in the pericardium, Pericardiocentesis is performed which means the fluid is drawn out from the area of pericardium.

The cytology, even if it is performed by expert pathologists, is not sufficient to make absolute diagnosis on the basis of presence or absence of malignant cells. If cytology demonstrates the absence of malignant cells, it lowers the suspicion of Mesothelioma, though not completely eliminates it.

It is quite difficult that the cytology alone will help the doctor determine the presence or absence of malignant Mesothelioma. It is, therefore, combined with biopsy to yield confirm results. A biopsy is required if successful diagnosis is the goal. It is done by removing a sample of tissue from the affected area, which is then examined under a microscope by a pathologist.

Depending on the areas that are affected, the ways to do biopsy can be different. For example, if chest is being inspected, a doctor will make a small cut through the chest wall and then inserts a thin tube which is lighted into the chest area between two ribs. The doctor will then looks into the chest through the tube or obtain tissue samples. This procedure is called thoracoscopy. Or sometimes, to make absolute diagnosis, instead of inserting the tube, the doctor may choose to perform thoracotomy and simply opens the chest.

Cancer in abdomen is determined through laparoscopy, and through a small cut in the abdomen, the instrument is inserted in the abdominal cavity to draw the tissue out for examination. If the doctor decides that these tests are not enough and do not yield sufficient results to make a sure diagnosis and therefore, the treatment also cannot start, more advanced examination is done through surgery.