Mesothelioma is an asbestos-caused cancer of the membranes that surround many of the body’s vital organs. This membrane, known as mesothelium, secretes a lubricating fluid that provides easy movement of the organs within the body. When the mesothelium becomes cancerous, it is called mesothelioma. Surrounding the lung, the mesothelium is called the pleura and the form of mesothelioma is called pleural mesothelioma; in the abdomen, it is the peritoneum and the cancer is called peritoneal mesothelioma; the lining around the heart is the pericardium and there mesothelioma is identified as pericardial mesothelioma. There is also mesothelial tissue in the reproductive organs: in males, this tissue is called the tunica vaginalis testis and in women the tunica serosa uteri. Mesothelioma of the reproductive tissues has only presented in men, so it is known as mesothelioma of the tunica vaginalis. 

Mesothelioma is a diffuse malignancy and spreads itself throughout a tissue area. Some forms of cancer are characterized by a single, solid tumor mass, whereas malignant mesothelioma presents as an invasion of a large number of smaller masses throughout an entire area. The diffuse nature of mesothelioma has important implications for how mesothelioma is treated, as complete surgical extraction of the cancerous tissue is difficult.

There are multiple forms of mesothelioma. The differences involve the location in which the tumor begins, known as its origin site, and the type of cells that the tumor invades, known as its histological subtype.

Location of Disease