The majority of mesotheliomas occur in the pleural (lung) cavity. Mesothelioma tumors may also found in the peritoneal (abdominal) cavity, the pericardium (heart) sac and, very rarely, the outer layer of the testicles (the tunica vaginalis).

Pleural mesothelioma is the most common type of mesothelioma, followed by peritoneal mesothelioma. The frequency of pericardial mesothelioma and testicular mesothelioma is quite low, and the symptoms are not well understood.

The symptoms associated with pleural mesothelioma tumors may be similar to other conditions affecting the lungs or chest. Pleural effusion, a complication of the disease, is the buildup of fluid in the chest. It may cause difficulty breathing.

Other common signs of pleural mesothelioma include:

• Pain
• Chest pain
• A dry (sometimes painful) cough
• Shortness of breath
• Difficulty swallowing
• Weakness and/or fatigue
• Back pain
• Unexplained weight loss

Tumors that develop in the membrane lining the abdominal cavity may cause pain in that area of the body. Common peritoneal mesothelioma symptoms include:

• Abdominal pain
• Accumulation of fluid in the abdomen (swelling)
• Diarrhea, constipation or other changes in bowel habits
• Unexplained weight loss

Next topic: What are the types of mesothelioma?