Diffuse malignant pleural mesothelioma, formerly known as malignant mesothelioma. Malignant mesothelioma is a malignant tumor with high invasion and primary pleura. Malignant pleural mesothelioma is the most common type of primary pleural tumor. Clinical manifestations are associated with aggressive behavior, which usually involves local invasion of the pleural space and surrounding structures. If untreated, the median survival is 4 to 12 months.
The pathogenesis and mechanism are still not very clear, which may be related to the following factors:
1. Long-term exposure to asbestos
Almost all types of asbestos fibers are related to the pathogenesis of mesothelioma, but the risk of each fiber is not the same, the most dangerous is exposure to chrysotile asbestos, the least risk is exposure to chrysotile asbestos. The incubation period from the first exposure to asbestos is generally 20 to 40 years, and the incidence of mesothelioma is proportional to the exposure time and severity. Evidence of asbestos-induced pleural mesothelioma:
(1) asbestos solution in animal experiments can induce pleural mesothelioma;
(2) asbestos fiber was found in malignant mesothelioma;
(3) for asbestos workers, especially those who have been working for 20 to 40 years, the incidence of mesothelioma found by autopsy is as high as 3.1%.
2. Other non-asbestos causes
Exposure to natural mineral fibers, chronic pleural infection (tuberculous pleurisy), and recurrent pulmonary infection. Cases of pleural mesothelioma caused by radiation exposure have also been reported. The time from exposure to radiation to the detection of pleural mesothelioma was 7 ~ 36 years, with an average of 16 years.
3. Ape disease 40SV40 (infection)
Thirty to fifty percent of patients with no history of asbestos exposure may be associated with SV40 infection. During the polio epidemic, millions of americans could become infected with SV40 from the Salk vaccine. Recently, SV40 has been isolated in patients with brain tumors and mesothelioma. Carbone and colleagues isolated SV40 fragments from 60% of mesothelioma patients and successfully induced mesothelioma after intrathoracic injection of SV40 into rats.