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What causes mesothelioma? Nearly every mesothelioma case is related to the inhalation of asbestos fibers. There are about 3,000 cases per year (mostly men over the age of 40) and there will be about 300,000 cases before 2030. The disease usually spreads rapidly through the mesothelial cells to the heart and abdominal organs. The life span is typically 24 months after diagnosis, but it depends on what stage the cancer is detected, the health of the patient and other factors. Although asbestos exposure causes mesothelioma, it has a latency period after exposure that could last 15 to 50 years. This means that someone who worked in a factory with asbestos 40 years ago could be developing the disease now. Anyone who knows they were exposed to loose asbestos fibers should be tested regularly. Gross Appearance Mesotheliomas display a wide range of histologic features.The malignant cells may appear epithelial or mesenchymal, or show features of intermediate differentiation (biphasic).The architectural and cellular features may range from well differentiated to anaplastic.The well differentiated tumors can be recognized by their light microscopic appearance, while more poorly differentiated tumors necessitate immunohistochemical and ultrastructural studies to reveal their identity.Mesotheliomas are also separated into four histologic categories:epithelial (50%), sarcomatous (15-20%), biphasic (15-20%), and poorly differentiated or undifferentiated (15-20%). |