Type of Mesothelioma
There are some classifications of mesothelioma's types:
Mesothelium type
Malignancy
Cellular types
1. Mesothelium type
Pleural mesothelioma
Pleural mesothelioma is a disease that affects the lining of the lungs, or lung pleura. Sometimes doctors refer to this disease as mesothelioma of the pleura.
Pleural mesothelioma spreads within the chest cavity, sometimes involving the lung. Metastases can occur in any organ, including the brain, and are much more common than previously thought.
The onset of mesothelioma is usually very slow, the most common presenting symptom is persistent pain localized in the chest. Sometimes the pain is generated by severe difficulty breathing, due to an accumulation of fluid in the pleural space known as pleural effusion.
The disease is caused by the inhalation of asbestos fibers that settle in the lungs. These asbestos fibers become inserted in the lung lining (the pleura). Over time, these fibers cause chronic inflammation that eventually leads to growth of cancerous tumors or, in some cases, asbestosis.
Pleural mesothelioma cancer normally appears as multiple tumor masses affecting the parietal surface (inside closer to the lung) and visceral surface (outside further from the lung) of the pleura.Large growths in the pleura are normally noted in patients upon diagnosis. These growths lead to a complete obliteration of the lung cavity later in the disease. The tumors can spread from the lung pleura to other organs, including the heart and abdomen. This aggressive disease can also invade the lymph nodes and blood system.
Peritoneal Mesothelioma
Mesothelioma of the abdomen is called peritoneal mesothelioma. The serous membrane surrounding the abdomen is known as the peritoneum. This disease accounts for approximately 10% to 20% of mesothelioma cases. In addition, a rare form of peritoneal mesothelioma affects the male testicles. The covering layer of the scrotum is actually an outpouching of the peritoneum. Peritoneal mesothelioma is due to the ingestion of fibrous materials, including asbestos.
Pericardial Mesothelioma
The rarest form of mesothelioma is that which affects the linings of the heart cavity, called the pericardium. Less than 10% of all mesothelioma cases are related to the heart. As in the lung, the rapid growth of the cancerous tumors can cause expansion of the tissue and accumulation of fluid. The fluid can interfere with the functioning of the heart and cause chest pain.
2. Malignancy
Benign mesothelioma
Benign mesothelioma is non-cancerous and can usually be removed and cured through surgery. A rare form of mesothelioma is the cycstic mesothelioma of the peritoneum. Its prognosis is benign. Its occurrence has been described primarily in young women. However the diagnosis presents difficulties, requiring extensive electron miscroscopy and immunohistochemical studies.
Malignant mesothelioma
Malignant mesothelioma is cancerous, and a very aggressive disease. The life expectancy for patients diagnosed with malignant mesothelioma ranges from 4-24 months since this cancer is difficult to treat and spreads rapidly.
3. Cellular types
Epithelial
The epithelial type of mesothelioma accounts for 50% to 70% of people diagnosed with mesothelioma, and has the best prognosis (slower growth, more likely to respond to treatment).
Sarcoma
The sarcoma type of mesothelioma accounts for 7% to 20% of people diagnosed with mesothelioma, and has a worse prognosis.
Mixed
The mixed type of mesothelioma accounts for 20% to 35% of people diagnosed with mesothelioma, and contains both epithelial and sarcomatous types. This type of mesothelioma has an intermediate prognosis.