The Pathophysiology of Mesothelioma

The three major and important histological types of mesotheliomas are sarcomatous mesothelioma, epithelial mesothelioma, and mixed mesothelioma.The pleural mesothelioma mostly begins as some discrete plaques and nodules that grow together or fuse to produce a sheet-like neoplasm. Tumor's growth usually begins at the lower most part of the chest. This tumor may invade the diaphragm and enclose the surface of the lung and inter-lobar fissures.This tumor may also grow in along drainage and all thoracotomy tracts.As the disease advances, it extends into the chest wall, mediastinum, and pulmonary parenchyma.The pleural mesothelioma may extend into the vertebra, brachial plexus, superior vena cava and of course ribs and esophagus, near sternum and posing a danger to lungs and other pleural structures.Asbestos is known as the number one carcinogen involved in the pathogenesis of this disease. The companies, factories, or industries associated with asbestos exposure include construction, paper mill, ship building, auto parts, railroad, ceramics and insulation industries. Many malignant mesotheliomas have complex karyotypes (photomicrograph of chromosomes arranged according to a standard classification), with extensive aneuploidy (chromosome number that is not a multiple of the haploid number for the species) and rearrangement of many other chromosomes.Loss of a single copy on (chromosome 22) is the most common abnormality.