Peritoneal mesothelioma, sometimes referred to as diffuse peritoneal mesothelioma, is a type of mesothelioma which affects the lining of the abdomen area. The peritoneum is a thin membrane which covers many organs in the human body. The tumor that is caused in this area can be either malignant or benign. The area affected can cause pressure on the organs, and depending on what areas the tumor affects, many other complications can occur. Excessive exposure to the harmful particle asbestos can cause peritoneal mesothelioma. Peritoneal mesothelioma is the second most common cancer which is caused by the particle asbestos, and also accounts for ten percent of all mesothelioma cases. There are many symptoms that are caused by peritoneal mesothelioma, but they aren’t unique symptoms, but rather symptoms which are common in many different types of diseases. These symptoms may include pains in the abdominal area as well as swelling in the area, a reduction in weight, nausea and a negative change in appetite, weakness, and bowel obstruction. Treating mesothelioma is very difficult, especially since once the disease is diagnosed, it is almost too late to treat. The patient only has a few months left to live after diagnosis. Treatment will be different for each patient; it really depends on how soon the diagnosis is made and how serious the disease is once it is diagnosed. There are many different types of treatment, which include: surgery, radiation therapy, and chemotherapy. Although peritoneal mesothelioma is not a curable disease as of yet, there are high hopes that with the advancement of technology, one day it can be cured.