Mesothelioma is a cancer that develops within the mesothelium of the body. The mesothelium is the protective covering in the body. It covers various organs, including the lungs. The mesothelium is made up of two thin layers. When cancer develops in the mesothelium it is between these layers. The narrow space makes it very difficult to diagnose mesothelioma in the early stages.
Mesothelioma is a difficult cancer to treat. Once a diagnosis of mesothelioma is made, the majority of patients will not live longer than eighteen months. There are a variety of reasons for this, including the advanced nature of the disease once it is diagnosed and the lack of an effective surgical method of removing the tumors.
While most cases of mesothelioma occur around the lungs, it can also occur in the abdominal mesothelium, called the peritoneum, or the pericardium. While mesothelioma is most common in the lungs, it is important to differentiate between mesothelioma and lung cancer. They are two very different types of cancer and require different types of treatment. The symptoms of mesothelioma include shortness of breath due to pleural effusion (fluid between the lung and the chest wall) or chest wall pain, and general symptoms such as weight loss. The diagnosis may be suspected with chest X-ray and CT scan, and is confirmed with a biopsy (tissue sample) and microscopic examination.
A thoracoscopy (inserting a tube with a camera into the chest) can be used to take biopsies. It allows the introduction of substances such as talc to obliterate the pleural space (called pleurodesis), which prevents more fluid from accumulating and pressing on the lung. Despite treatment with chemotherapy, radiation therapy or sometimes surgery, the disease carries a poor prognosis. Research about screening tests for the early detection of mesothelioma is ongoing. Diagnosing mesothelioma is often difficult, because the symptoms are similar to those of a number of other conditions. Diagnosis begins with a review of the patient’s medical history. A history of exposure to asbestos may increase clinical suspicion for mesothelioma.