Mesothelioma is a malignant tumor originating in the mesothelial cells that make up most of the body foils (special structures, very fine, bounding cavities), including the pleura, peritoneum and pericardium. Malignant mesotheliomas are relatively rare tumors that can be localized to a specific region or may have a diffuse character.
Of these, the most common location is the lung (pleural ie, in 90% of cases). Mesothelioma lung is associated with prolonged exposure to asbestos dust patient. Examining plots of many patients diagnosed with mesothelioma lung and analyzing occupational exposure and individual risk factors, scientists have concluded that over 75% of all cases can be linked to exposure to asbestos.
Diagnosing mesothelioma is often difficult and complicated process because of accompanying pleural fluid of mesothelioma may not have specific characters do not serve so much to establish with precision the origin of pleural effusion.
Malignant mesothelioma lung fecvent occurs in men after the fifth decade of age, with a peak incidence at 35-45 years after exposure to asbestos. The incidence of mesothelioma is reported to be low, about 1 in 100,000 people diagnosed annually. However, due to increasing pollution, there is a risk that in future cases to be more frequent. Patients in polluted industrial areas have a risk of 2 to 10 times more likely to develop such a cancer.
Although the incidence is low, the prognosis of patients with mesothelioma is always severe and unfavorable. The disease is almost always fatal. It is considered that the average survival after diagnosis is about 11 months (differs slightly depending on histological subtype: 9 months for sarcomatous variant, the 13 months to 11 months for the epithelial and mixed).
The most important cause of developing a mesothelioma is exposure to asbestos. This can be done in buildings with asbestos-based material in the factories that produce this material in mines, shipyards. Asbestos is a material with important physical properties used in thermal insulation of buildings, dwellings, in ceilings, in concrete and even in certain parts of vehicles.
Malignant mesothelioma has been correlated with the development of medical imaging tests, or application of radiation therapy (to treat other types of cancer). Also, experts have suggested lately and a correlation between exposure to simian virus 40 and subsequent development of cancer. However, studies tend to show that a carcinogenic virus and not as an agent able to induce this neoplasia through individual action.
Although a very high number of patients and a long history of smoking, experts are reluctant to criminalize smoking in the development of this particular type of cancer. Mesothelioma can be of three types: sarcomatous mesothelioma, epithelial or mixed. Evolution of tumor is quite long and begins in the form of small node, which in turn will expand, including free zones around.
The tumor usually occurs in the lower regions of the mediastinum, the pleura of the lung bases, and may extend lower, including in the cancerous and aperture. As the disease progresses, enough to expand and lung parenchyma, chest wall and mediastinum, sometimes even into the esophagus, ribs, vertebrae, brachial plexus.
The average age of diagnosis of the disease is about 60 years, most patients were men who worked in construction, the shipyards, the railway, mining and automotive industry. Because asbestos dust can wear and carry clothes, unintentionally expose these workers and their families at risk of developing pleural mesothelioma.
Although the incidence of mesothelioma is reported to be relatively low, experts have observed that today we face a growing trend of it, due to excessive pollution. Although theoretically the 1960s industrial and domestic use of asbestos should be reduced (or even banned), there are still many cases of the disease since the time of appearance of symptoms is very long.
Symptoms Malignant mesotheliomas occur after prolonged exposure to asbestos dust, and no sooner than 20-50 years of contact.
The most common symptoms include:
- Abdominal bloating;
- Abdominal pain
- Chest pain or discomfort;
- Shortness of breath;
- Fatigue, sweating;
- Weight loss.
Dyspnea and chest pain are the most common complaints nonpleuritica where Malignant mesotheliomas. Approximately 60-90% of patients present to the doctor with these symptoms. More than 50% of patients there is pleural effusion (accumulation of fluid in the pleural space pathology).
In some cases the patient may be very long and asymptomatic pleural effusion, or local changes in the lung can be observed after performing some routine investigations, or to diagnose other diseases
Diagnosing mesothelioma is relatively difficult because signs and symptoms are nonspecific. It is therefore very important that history be made carefully, because the recognition of a patient’s exposure to asbestos in history can focus very much diagnosis. Mesotheliomas are located mainly in the pleura, especially on the right side (in 90% of cases), and in the peritoneum (5%), pericarditis (0.5%).
Physical examination is very important because the chest auscultation and percussion can identify the presence of pleural effusion. Distinguishing marks only appear in very few cases, when the tumor is so advanced that cause cardiac compression, brachial plexopathy, Horner syndrome or superior vena cava syndrome.
Because this disease is very common, it must be differentiated from other diseases with similar clinical tabolu that can evolve with pleural effusion. Most times they are small cell lung cancer, mesothelial hyperplasia, pulmonary fibrosis, chronic lung infections.
Paraclinical investigation include the development of the patient laboratory measurements but imagisitice that can establish the diagnosis of certainty. Imaging tests are those that can establish the existence of pleural effusion, the expansion process and the existence of other sites of mezotelioamelor. Most often performed chest radiographs, computed tomography (CT), magnetic resonance imaging (MRI).
If it highlights the existence of a pleural effusion is very important achievement of purpose puncture to harvest liquid can then be analyzed. Although fluid cytology may be positive in many cases, there is the possibility that it does not provide useful information and not to assist the diagnosis. It is important to note that the severity of the patient’s condition and prognosis are influenced by the amount of pleural effusion present.
The diagnosis of malignant mesothelioma can be determined by:
- Highlighting pleural effusion, which decreases the amount after performing thoracentesis;
- Harvesting a tissue fragment by thoracoscopic pleural biopsy (may establish correct diagnosis in over 98% of cases). Biopsy results, although specific diagnoses, but come rather late.
Pathological analysis of extracted tissue fragments may determine the histopathological type and stage of the mesothelioma. Best epithelial mesothelioma prognosis have it.
Mesothelioma can be staged as follows:
- Stage I: The tumor capsule respect, not invade surrounding structures, is located, has no accompanying lymphadenopathy. At this stage the tumor is completely resected;
- Stage II: The tumor has the characteristics of stage I, but has intrapleural adenopathy;
- Stage III: Local extension exists in the mediastinum or chest wall, the pericardium or the diaphragm or peritoneum liungul and extrapleural lymph node involvement;
- Stage IV: The tumor has metastasized to distant.
Malignant mesotheliomas therapeutic options include surgery, chemotherapy, radiotherapy or multimodal scheme. If neoplasia is limited and localized in the pleural space, surgery may be indicated. As the disease progresses very long relatively asymptomatic and the diagnosis is made late, the treatment is often exceeded, the cancer becomes incurable. Patient survival period varies depending on the histological type of mesothelioma, but the average is 9 months.
Chemotherapy mesotheliomas have often done by using combinations. The best results were recorded using cisplatin and gemcitabine. But the results are not scared. Radiation therapy is also used in palliative only, not influence survival rates, and may improve quality of life (reducing chest pain and progression of metastasis in the chest wall) to half of patients with advanced mesothelioma.
Trimodal therapy includes a combination of the above three methods (surgery, chemotherapy, radiotherapy). You can try making an extrapleural pneumonectomies followed by chemotherapy and radiotherapy. But the survival rate is only 45% at 2 years and 22% at 5 years. Symptomatic treatment is often the best that can improve the patient’s condition. Indicated strong analgesics, opioids for pain management class and oxygen therapy.
Survival is currently the treatment (very wide) between 16-18 months. Very few patients survive to five years, even in the presence of treatment. The prognosis is reserved in all cases and depends heavily on:
- Histological type of cancer;
- The state in which to start treatment (if greater than II survival is greatly reduced);
- Therapeutic possibilities;
- Chest pain intensity felt;
- Hemoglobin level (it is lower, the prognosis is worse);
- LDH levels greater than 500 IU / L;
- Patient age at diagnosis;
Some possible complications include:
- Recurrent in 50% of cases surgical treatment;
- Involvement of other tissues;
- Spreading generally very fast.
Seeing a specialist
Patients are advised to go to the doctor for testing and treatment if they notice the appearance of local symptoms suggestive of a lung disease, unintentional weight to drop, especially if they had jobs at risk and have been exposed to asbestos.
The best way of preventing Malignant mesotheliomas is to avoid exposure to asbestos.