Malignant mesothelioma

Malignant mesothelioma (me-zo-thee-le-O-muh) is a rare cancer that occurs in the thin layer of tissue that covers the majority of your internal organs (mesothelium).

Doctors divide mesothelioma into different types based on what part of the mesothelium is affected, including:

•Pleural malignant mesothelioma, which affects the tissue that surrounds the lungs and is the most common form of mesothelioma.
•Peritoneal mesothelioma, which occurs in the tissue in your abdomen.
•Pericardial mesothelioma, which affects the tissue surrounding the heart.
•Mesothelioma of the tunica vaginalis, which occurs in the lining around the testicles.
Between 2,000 and 3,000 people are diagnosed with mesothelioma in the United States each year, according to the American Cancer Society.

Signs and symptoms of mesothelioma vary depending on where the cancer occurs.

Pleural mesothelioma signs and symptoms may include:

Shortness of breath
Painful breathing (pleurisy)
Painful coughing
Chest pain under the rib cage
Unusual lumps of tissue under the skin on your chest
Unexplained weight loss
Dry (nonproductive) cough
Peritoneal mesothelioma signs and symptoms may include:

Abdominal pain
Abdominal swelling
A change in your bowel habits, such as more frequent diarrhea or constipation
Lumps of tissue in the abdomen
Unexplained weight loss
Other forms of mesothelioma
Signs and symptoms of pericardial mesothelioma and mesothelioma of the tunica vaginalis are unclear. These forms are so rare that not much information is available. Pericardial mesothelioma signs and symptoms may include difficulty breathing or chest pains. Mesothelioma of the tunica vaginalis may be first detected as a mass on a testicle.

When to see a doctor
See your doctor if you have signs and symptoms that may indicate mesothelioma. Signs and symptoms of mesothelioma aren't specific to this disease and, due to the rarity of mesothelioma, are more likely to be related to other conditions. If any persistent signs and symptoms seem unusual or bothersome to you, ask your doctor to evaluate them.