Free Mesothelioma Information Packet

Benign Mesothelioma

While the vast majority of mesothelioma cases are malignant, benign - or non-malignant - mesothelioma can occur in some cases.

Benign Mesothelioma Tissue

What is Benign Mesothelioma?

More recently referred to as a "solitary fibrous tumor of the pleura," benign mesothelioma - as the name indicates - is usually not cancerous, though cancerous forms can occur from time to time.

Appearing more in men than women, these tumors usually start in the tissues under the mesothelium, which is known as the submesothelium. A similar tumor may grow in the peritoneum, the lining of the abdomen. Doctors have appropriately named that disease "solitary fibrous tumor of the peritoneum."

Why is this Tumor Different?

The most important difference between these benign mesothelioma tumors and the cancerous forms is that these tumors do not spread, invading adjacent tissue. On the other hand, malignant tumors often spread quite quickly, making mesothelioma treatment difficult and non-effective.

Symptoms of Benign Mesothelioma

Benign mesotheliomas are actually very rare. They account for less than 10 percent of all mesothelioma cases worldwide. However, they do occur, usually presenting symptoms that are quite similar to those connected with malignant pleural mesothelioma. As a matter of fact, it is nearly impossible to differentiate between the two without extensive testing or surgical procedures.

The most common mesothelioma symptoms that may indicate the presence of a solitary fibrous tumor of the pleura are:

  • Chest pain
  • Shortness of breath
  • Chronic cough

The major reason for these symptoms is usually the growth of the benign tumor, which may be pressing on the lungs.

The doctor may also spot a clubbed appearance of the fingers, which is often a sign of such a tumor. With clubbed fingers, the nail bed takes on a distorted angle, which is indicative of a dangerously low level of oxygen in the blood. Clubbing is often associated with both lung cancers and heart diseases as well as cystic fibrosis.

Diagnosing Benign Mesothelioma

The same tests used for diagnosing malignant mesothelioma are used for diagnosing the benign form, because it's impossible to distinguish one from the other without the aid of sophisticated imaging or other procedures. The doctor may first suggest a regular x-ray, followed by a:

  • CT scan

    Images produced by a machine that consists of an x-ray-generating device that rotates around the entire body. The device, which is connected to a high-tech computer, provides cross-section images (or "slices") of the inside of the body.

  • MRI

    A diagnostic tool that uses a magnetic field and radio waves to create cross-sectional images of the head or body. This test has proven especially successful in detecting tumors in or around the lungs, which makes it especially useful for diagnosing mesothelioma.

Though these tests can provide excellent pictures of the lungs and other affected areas, most doctors now opt for an open lung biopsy in order to reach a definitive conclusion. This biopsy involves surgery under general anesthesia, during which a small piece of the lung tissue will be removed and sent to a pathologist for examination.

Treatment of Benign Mesothelioma

Cases of benign mesothelioma are easily treatable, unlike malignant mesothelioma. In mose cases mesotheliom surgery to remove the tumor is usually sufficient. The prognosis is usually excellent in these cases.


The development of benign mesothelioma could be an indication that more serious mesothelioma-type diseases may develop in the future. Anyone diagnosed with benign mesothelioma should continue with regular check-ups and chest x-rays after surgery.


Last modified: April 07, 2010.