The form of cancer called mesothelioma is mainly caused by exposure to asbestos. It is one of the most aggressive forms of cancer and also very difficult to treat. The main reason for being so difficult to treat is the late diagnose, due to the lack of symptoms during the early stages. Another reason for late diagnosis is that most people are simply unaware of their exposure to asbestos, so they never think of checking this disease. This type of cancer affects the mesothelium cells. Mesothelium is the protective membrane of most internal organs.
There are mesothelioma forms which are malignant, but also some which are benign. Medical terminology defines as mesothelioma only that form which is malignant. Mesothelioma cells appear differently under the microscope, so they are divided in four main categories.
Epithelioid cells are the most common type of mesothelioma cells. Between 50 % and 70 % of the mesothelioma cases are of this type. This form of cancer has comparatively high chances to be cured.
Sarcomatoid (fibrous) cells are a rare type of mesothelioma cells, which occur in 7% to 20 % of the cases. This form of mesothelioma affects also secondary tissues, this is why the rate of survival is low.
Mixed (biphasic) cells implies that both sarcomatoid and epithelioid cells are found simultaneously. This form of mesothelioma is present in 20 % up to 35 % of the cases.
Desmoplastic cells are the rarest mesothelioma cells. The rate of survival in this case is quite low.
Depending on which part of the body is affected by mesothelioma, it has different names.
Pleura mesothelioma is the one affecting the membrane covering the lungs and it is the most common. 75% of the mesothelioma cases are pleura mesothelioma. It is mainly caused by the inhaling of asbestos fibers which lead to inflammation and scarring of the pleura, which develops into cancer.