Diagnosis of Mesothelioma -
Mesothelioma Diagnosis, Pleural Mesothelioma
The Diagnosis of Mesothelioma
Malignant mesothelioma is a relatively uncommon type of cancer; fewer than 3,000 cases are reported each year. The disease is named mesothelioma because it attacks the mesothelium, a tissue that lines and lubricates various large body cavities, including the:
- Pleura (thoracic cavity or lung)
- Peritoneum (abdominal cavity or stomach)
- Pericardium (heart sac)
Malignant mesothelioma therefore takes on three distinct forms:
- Pleural Mesothelioma: mesothelioma of the thoracic cavity.
- Peritoneal Mesothelioma: mesothelioma of the abdominal cavity.
- Pericardial Mesothelioma: mesothelioma of the heart sac.
Most malignant mesothelioma cases can be traced back to some type of asbestos exposure. Asbestos exposure is the only known cause of malignant mesothelioma; however, there are a number of asbestos lung diseases related to inhalation of the fibrous mineral, such as asbestos lung cancer, asbestosis and pleural plaque / fibrosis.
Symptoms of Mesothelioma
Pleural mesothelioma is the most common type of mesothelioma. Early symptoms of pleural mesothelioma are sometimes misdiagnosed because of their similarity to viral pneumonia.
Pleural mesothelioma symptoms include:
- Shortness of breath
- Chest pain (most common presenting symptom)
- A chronic cough
- Weight loss
- Fever
Peritoneal mesothelioma is the second most common type of mesothelioma. Peritoneal mesothelioma symptoms include:
- Abdominal pain
- Abdominal swelling
- Weight loss
- Bowel obstructions
- Blood clotting abnormalities
- Lowered red blood cell count (anemia)
- Fever
Pericardial mesothelioma is the least common type of mesothelioma, causing cancerous growths in the heart sac. Pericardial mesothelioma symptoms include:
- Chest pain
- Abnormal breathing (dyspnea)
- Irregular heartbeat (palpitations)
- Cough
People suffering from any of the aforementioned symptoms are recommended to consult a doctor as soon as possible.
Diagnosis of Mesothelioma
Early diagnosis of mesothelioma can be tricky because of the latency period between contraction and display of symptoms. Unfortunately, once malignant mesothelioma is diagnosed, it is usually in an advanced stage. This results in an average survival time following diagnosis of between one and two years.
Mesothelioma diagnosis typically begins with a patient's visit to the doctor, complaining of chest pain and shortness of breath. Following an x-ray or MRI, mesothelioma is normally detected as a pleural effusion (fluid buildup inside the thoracic cavity, around the lung). The disease is often misdiagnosed at this point because of the symptomatic similarities between pleural mesothelioma and viral pneumonia.
In order to verify whether or not a patient suffering from pleural effusion has in fact developed pleural mesothelioma, a sample of suspect tissue has to be surgically removed for examination by a pathologist (a process commonly referred to as a biopsy). Accessing the pleural cavity is achieved by cutting through the chest wall (a thoracoscopy) using a special instrument called a thoracoscope.
Relief from pleural effusion can be achieved through thoracentesis, an invasive procedure designed to remove fluid or air from the pleural space. Also known as a pleural tap, thoracentesis provides temporary relief from pleural effusion; however, it also serves as a diagnostic guide for a variety of diseases, ranging from cancer and autoimmune disease, to pancreatitis and cirrhosis.
If the doctor suspects peritoneal mesothelioma, he may perform a peritoneoscopy (cutting a small opening in the abdominal cavity) to obtain tissue samples.
The biopsy itself can be completed in one of two ways:
Incisional Biopsy: (core biopsy) this procedure removes a small sample of suspect tissue for examination.
Excisional Biopsy: this procedure removes an entire suspect area for examination.
Removed tissue is sent to a pathologist who uses a high-powered microscope to examine the tissue for irregularities (this process is commonly referred to as histopathology). If a biopsy returns a positive diagnosis of mesothelioma, the next step is to stage the disease. Staging involves a series of tests designed to determine how advanced a case of malignant mesothelioma is. There are a number of staging systems used to designate a cancer stage, most of which use a Roman Numeral scale of I to IV (I being the most treatable stage, IV being the most advanced stage).
In addition to the highly descriptive scaling method of staging, there is also a general method:
- Localized stage: mesothelioma is localized if the disease is found only in the area it originated.
- Advanced stage: mesothelioma is advanced if it has spread beyond the original location to other parts of the body.
Staging a case of malignant mesothelioma identifies the best direction that treatment should be taken.