Mesothelioma

Mesothelioma means cancer of the mesothelium (-oma is a medical term for tumor or cancer). The mesothelium is the sac that lines and protects vital organs such as the heart, the lungs, and the abdominal cavity (stomach). This disease causes the cells of the lining to become abnormal and malignant. About two thirds of all mesothelioma cases develop in the pleural mesothelium or lung lining. The remaining cases, about one third, develop in the abdomen. Rarely, mesothelioma occurs in other mesothelial tissue, such as around the heart or in the reproductive organs.

Without treatment, most patients will die from mesothelioma within 4 to 12 months from the time of diagnosis. Patients generally die as a result of respiratory failure or pneumonia. Small bowel obstruction, resulting from direct extension of tumor through the diaphragm, develops in about one-third of patients. About 10% die of cardiac complications when the tumor invades the pericardium and heart. Three subtypes of mesothelioma have been identified according to microscopic appearance; these are epithelial, sarcomatoid, and mixed types. A number of studies have demonstrated that the epithelial variant is associated with the best prognosis. Other favorable prognostic variables include younger age, good performance status, early stage disease, and lack of chest pain at diagnosis.