Mesothelioma- An Overview of Types , Symptoms and Cures

Mesotheliomas are tumours that arise from mesothelial cells.These cells form the tissues covering most of our internal organs and cavities and are responsible for protecting the internal surfaces and providing lubrication.The cancer of such cells is termed mesothelioma. These mainly affect the pleura, peritoneum, pericardium and the heart.

Mesothelioma of Pleura

Pleura is the outer tissue covering the lungs.Malignant mesotheliomas are primary tumours that arise from the mesothelial cells that line the pleural cavities.These tumours do not appear to be associated with smoking.They are related to asbestos exposure.Short term asbestos exposures of one to two years occuring 20 to 25 years in the past have been associated with the development of mesotheliomas.Risk for the tumour peaks 30 to 35 years after initial exposure. Since maximum exposure took place in the US between 1930 and 1960 ,peak incidence of disease in men occured during the 90s with a total of 2300 cases in 1997 alone.Incidence is expected to decline over the next 30 years to about 500 cases per year.

Patients with pleural mesothelioma shows chest pain and shortness of breath.The chest radiograph reveals a pleural effusion , generalised pleural thickening and a shrunken hemithorase. Open pleural biopsy or Thoracoscopy is usually necessary to establish diagnosis. Although approximately 50% of mesotheliomas metastasize , the tumour generally is locally invasive. Death usually occurs from local extension. Various treatment modalities include radical surgery, chemotherapy and radiation therapy,but none has been proven to be more effective than symptomatic therapy. It is recommended that chest pain be treated with opiates and breathlessness with oxygen.

Mesothelioma of Peritoneum

Peritoneum is the lining of the abdominal cavities.Like pleural mesothelioma , this is also a highly malignant tumour. Asbestos is the prime recognised cause. It has a predilection for the pelvic peritoneum, but it is not radiosensitive. Alkylating agents have given remissions. Recent regimens of multiple chemocytotoxic agents have been reported as curative for early forms of malignant mesothelioma.Benign forms are also reported rarely.

Mesothelioma of Pericardium

The most common primary malignant tumour of pericardium, the outer covering of the human heart, is mesothelioma. It causes pericardial effusion which is bloody.Surgical exploration is required to establish a diagnosis and for palliative treatment.

Mesothelioma of heart

They are generally small tumours most often found in intramyocardial sites and may cause disturbances in the flow of blood through arteries and veins and even sudden death as a result of their predilection for the region of the AV node.

General Diagnosis

Xray -can reveal pleural fluid build up in either chest.Scarring due to asbestos can also be seen.

CT Scan -CT scans may also be valuable in guiding fine needle aspiration of pleural masses for tissue diagnosis.

MRI -It is much more accurate and useful than xrays and ct scans as it scans the body in different planes and hence helps to identify the extent of the tumour.

Positron Emission Tomography (PET)- While PET scans are more expensive than other types of imaging, and are not always covered under insurance, they are now considered to be the most diagnostic of tumor sites, as well as the most superior in determining the staging of mesothelioma.

Others include thoracoscopy,peritoneoscopy and biopsy. Study of the particular tissue mass is utterly helpful and hence pathology has a role to play.Mesothelioma is often difficult to differentiate from adenocarcinoma and hence immunohistochemical markers may be used for the same.

General Treatment Methods

The course of treatment depends on

The type of mesothelioma and location of the tumor

The size of the tumor(s)

The degree to which the cancer has spread or metastasized

The stage of the cancer - beginning, advanced, etc.

The age of the patient

The overall physical health of the patient

Surgery - Surgery is most often used either to try to cure the disease or , as in most practical situations, to enable the patients to suffer less due to the disease.

Radiation Therapy- External beam radiation can be used to target particular areas of tissues and hence destroy the cancer cells.Compared to chemotherapy there are less side effects.

Chemotherapy - It cannot completely cure the disease, but it can provide temporary release, but there are side effects.

Plenty of research is being done in the field for the cure of diseases due to chemical exposure like mesothelioma . Many new methods of treatment are evolving. Since they are only in the testing stage, no authentic information is available.As medical science and technology join hands to fight such disease, there is definitely hope for those who are suffering in the deathly grasp of the disease.