Malignant mesothelioma is a rare type of cancer caused by breathing in asbestos fibers.1 The type of mesothelioma is determined by where the cancer originates.
Pleural mesothelioma starts in the chest cavity in the lining around the lungs, called the pleura. This form of the disease accounts for 75 percent of malignant mesothelioma cases. Pleural mesothelioma can spread to the lining of the heart, which is more difficult to treat.2
The most common symptom of pleural mesothelioma is chronic chest pain, but chronic coughing, difficulty breathing, fever and weight loss are also symptoms.3 Pleural mesothelioma treatment can involve surgery as simple as removing the tumor, or as complex as removing part of the lungs and diaphragm. Chemotherapy and radiation are also standard treatments.4
Peritoneal mesothelioma starts in the lining of the abdomen, called the peritoneum. Abdominal mesothelioma makes up 10 to 20 percent of malignant mesothelioma cases, resulting in approximately 250 new cases each year.5 Peritoneal mesothelioma is caused by swallowing the asbestos fibers after inhaling them.3
The symptoms associated with peritoneal mesothelioma are swelling and pain in the abdomen, fever, weight loss, anemia and bowel obstruction or an abdominal mass.3 Treatment currently consists of surgically removing the tumor and chemotherapy.5
Pericardial mesothelioma3 is very rare, with the tumor starting in the lining, or sac, around the heart. The tumor constricts the heart’s function and is usually removed surgically as soon as possible after diagnosis. Fewer than 200 cases of this form of malignant mesothelioma have been reported. The symptoms mimic pleural mesothelioma but are accompanied by an irregular heartbeat and fluid buildup in the chest.
Other types of mesothelioma
The rarest form of malignant mesothelioma starts in the lower part of the peritoneum in men — called mesothelioma of the tunica vaginalis testis. It appears as fluid accumulation in the scrotum and requires removal of the affected testicle.3 A similar form of this tumor in women is papillary mesothelioma, but it is benign and does not cause cancer.6
Benign mesothelioma is generally not caused by asbestos exposure, and these tumors rarely spread.7 However, most types of mesothelioma (that is, malignant mesothelioma) can spread and require early treatment.8