A biopsy is needed to confirm a mesothelioma diagnosis. In a biopsy, a surgeon or a medical oncologist (a doctor who specializes in diagnosing and treating cancer) removes a sample of tissue for examination under a microscope by a pathologist. A biopsy may be performed in different ways, depending on where the abnormal area is located.
If the cancer is in the chest, the doctor may perform a thoracoscopy. In this procedure, the doctor makes a small cut through the chest wall and puts a thin, lighted tube called a thoracoscope into the chest between two ribs. Thoracoscopy allows the doctor to look inside the chest and obtain tissue samples.
If the cancer is in the abdomen, the doctor may perform a peritoneoscopy. To obtain tissue for examination, the doctor makes a small opening in the abdomen and inserts a special instrument called a peritoneoscope into the abdominal cavity.
If these procedures do not yield enough tissue to make a diagnosis, more extensive diagnostic surgery may be necessary.
If the doctor makes a diagnosis of mesothelioma, he or she will want to determine the mesothelioma stage.
Staging involves more tests in a careful attempt to learn whether the cancer has spread and, if so, to which parts of the body. Knowing the stage of the disease helps the doctor plan mesothelioma treatment.
Mesothelioma is described as localized if the cancer is found only on the membrane surface where it originated. It is classified as advanced if it has spread beyond the original membrane surface to other parts of the body, such as the lymph nodes, lungs, chest wall, or abdominal organs.
(Click Mesothelioma Stages for more information.)