Mesothelioma Cancer
What is mesothelioma?
The mesothelioma is cancer of the cells making up the lining around the outside of the lungs and inside of the ribs (pleura), or around the abdominal organs (peritoneum). Mesothelioma is a very rare type of cancer in which cancer cells invade the mesothelium, the protective cover that covers most internal organs.
What has to do with asbestos mesothelioma?
The only known cause of mesothelioma in the U.S. is previous exposure to asbestos fibers. The asbestos manufacturers knew of the dangers of asbestos seventy years ago – but they kept this knowledge secret. The first warnings of danger which gave the workers were in the mid-1960s, and these warnings were terribly inadequate. Even today, they are not always informs workers that are working around asbestos and are at risk of contracting an asbestos disease.
The mesothelium is composed of two layers of cells: one layer is in contact with the organ, while the latter forms a bag around. The mesothelium produces a lubricating fluid that allows the layers to slide over one another allowing the movements of the body covering (eg, lungs). Depending on their position, the mesothelium get a particular name: the one that surrounds the lungs is called pleura, around the heart called pericardium, which surrounds the testicles is called the tunica vaginalis testis and surrounding the uterus is called uterine serous tunic. Most abdominal organs are covered by peritoneum.
Pleural Mesothelioma
Pleural Mesothelioma is the most common, its incidence being 9 times higher than the peritoneal mesothelioma. It is more common in men than in women, being the age of onset of symptoms between 50 to 70 years with a latency period of 20 to 40 years. In 80% of cases the etiology is exposure to asbestos dust. Other possible causes of mesothelioma are radiation therapy and polio vaccines contaminated with simian virus SV40. The pleural mesothelioma is about 3% of malignant neoplasms of the pleura, and when the diagnosis is made rapidly and its course is invariably fatal, usually during the next two years.
The most common clinical presentation is diffuse chest pain, which occasionally can be pleuritic or radiating to the shoulder accompanied by pleural effusions. Dyspnea, cough, weakness, malaise and fatigue are usually in advanced stages of disease. In 89% of cases, the abnormal electrocardiogram abnormalities being more frequent sinus tachycardia (42%), ventricular or atrial arrhythmias (17%) and blockage of a branch bundle (30%)
The most common radiographic finding is of an irregular opacity in the lung periphery, associated with ipsilateral pleural effusion, with evidence of deflation, contraction of the hemithorax committed and no shift of the mediastinum to the opposite side, despite significant pleural effusions (*) The diagnosis should be suspected when pleural thickening is found surrounding the lung trap and secured to the mediastinum.
From the histological point of view, the mesoepitelioma is classified into 3 types:
* Epithelioid covering 50% of cases and generally better prognosis and life expectancy;
* Sarcomatoid happens between 7 to 20% of cases;
* Mixed or biphasic occurs in 20 to 35% of cases,
Diagnosis of Pleural Mesothelioma
The diagnosis of pleural mesothelioma is often difficult because the symptoms are similar to many other conditions. The diagnosis begins with a review of medical history, followed by a complete physical examination including a chest radiograph and pulmonary function studies. CT and MRI can be useful in determining the extent and location of the lesion.
To confirm the diagnosis requires a biopsy can be done by thoracoscopy (*) or, if this is not possible through conventional surgery. Once the existence doagnóstico, determine that the stage of the disease in order to proceed with the best treatment