Describe mesothelioma and its cause.
Mesothelioma is a malignant inflammation of the mesothelial cells, most commonly those covering the lung. The mesothelial coverings of the heart and abdominal cavity may also rarely be involved. This inflammation is caused by inhalation of asbestos materials, usually during prolonged occupational asbestos exposure. However, there is no minimum amount of asbestos exposure that has been correlated with development of this disease. Mesothelioma generally presents with shortness of breath and chest pain. The majority of patients with have a pleural effusion visible on plain radiographs and CT scan. However, a thoracotomy and open biopsy are generally considered the definitive method of diagnosis. Life expectancy at diagnosis is generally poor with estimations between 7 and 15 months. Treatment may include palliative care, surgical excision, or chemotherapy.