Written By: Devin Golden

Benign Mesothelioma

Benign mesothelioma is a noncancerous case of mesothelioma. Benign tumors can be surgically removed.

Karen Ritter, RN BSN

Medically Reviewed By

Karen Ritter, RN BSN

Registered Nurse

Karen Ritter, RN BSN

Medically Reviewed By

Karen Ritter, RN BSN

Registered Nurse


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What Is Benign Mesothelioma?

Benign mesothelioma is a noncancerous tumor growth derived from mesothelial cells. It is the opposite of malignant mesothelioma, which is cancerous and deadly. Benign tumors are not “active,” which means they are not spreading.

Benign mesothelioma forms primarily in the pleura (protective lining near the lungs) or peritoneum (protective lining around the abdominal cavity).

Benign Mesothelioma vs. Malignant Mesothelioma

Benign mesothelioma and malignant mesothelioma are different in many ways. Some of the most important contrasts between the two are:

  • Rates of occurrence
  • Relationship to asbestos
  • Discovery and diagnostic process
  • Symptoms
  • Treatment options and length of time
  • Prognosis and survival time

Rarity and Relationship to Asbestos

There are around 3,000 new mesothelioma cases each year in the United States. Almost all of them are malignant mesothelioma.

Benign mesothelioma mostly affects women, whereas malignant mesothelioma primarily affects men.

Malignant mesothelioma is linked to asbestos, but the cause of benign mesothelioma is unknown. There is not an established relationship between benign mesothelioma and exposure to asbestos.

Discovering and Diagnosing Each Mesothelioma

Benign mesothelioma is often discovered by accident. Since the tumors aren’t growing and spreading, there are usually few noticeable signs. By comparison, malignant mesothelioma can lead to severe symptoms.

Benign mesothelioma often is discovered through imaging tests after patients experience pain in the abdomen or chest. However, a tissue biopsy is the best method for diagnosis.

How to Treat Each Mesothelioma

A benign disease usually needs just surgery. Resecting the stagnant tumor growth is the most effective way to ensure it doesn’t regain active state. Malignant mesothelioma is tougher to remove and often requires multiple lines of treatment (surgery, chemotherapy and radiation).

The surgeries used for benign mesothelioma are the same as those used for malignant mesothelioma:

Benign patients may undergo fluid-draining procedures to relieve symptoms.

Symptoms and Survival

Benign mesothelioma symptoms usually aren’t as severe as malignant mesothelioma symptoms. Since tumors exist in the thorax or abdomen, they can press against organs or cause excessive fluid buildup. Chest or abdominal pains are possible.

Survival is much better for benign cases than it is for malignant ones. The prognosis is better because benign tumors do not spread throughout the body.

The disease is isolated, which leaves the majority of the tissue unaffected and healthy. Surgery is also more effective for an isolated, smaller disease.

Types of Benign Mesothelioma

There are several types of benign mesothelioma, all of which are rare. Benign mesothelioma varies based on location and cellular structure.

Most develop in the lining of the abdomen (the peritoneum).

Benign Multicystic Mesothelioma

Benign multicystic mesothelioma originates in the peritoneum and mostly affects women. This type of tumor usually affects women between ages 20 and 40.

One study reported the mean age of female patients was 36. Benign multicystic peritoneal mesothelioma can affect men, and the mean age of male patients is 67.

There have been fewer than 200 documented cases of benign multicystic peritoneal mesothelioma.

The most common symptoms include:

  • Abdominal pain
  • Swelling
  • Ascites (fluid buildup in the peritoneum)

Well-Differentiated Papillary Mesothelioma

Well-differentiated papillary mesothelioma is a slow-growing or stagnant type of epithelioid mesothelioma. Its growth and spread is so slow that it’s considered a benign disease.

Similar to benign multicystic mesothelioma, well-differentiated papillary mesothelioma often appears in the peritoneum of young women. A study published in the Annals of Diagnostic Pathology found 75 cases of this type of benign mesothelioma: 58 involved females and 17 involved males. The mean age was 42.

Of the 75 cases, only one turned into a malignant mesothelioma.

The symptoms of well-differentiated papillary mesothelioma in the peritoneum are similar to multicystic mesothelioma: fluid buildup and abdominal pain.

Adenomatoid Mesothelioma

Adenomatoid mesothelioma is a rare, benign disease forming from mesothelial cells. This benign cancer usually forms in the genitals.

Tumors can form near the lungs, but it’s extremely rare. Adenomatoid mesothelioma is most common in males, with a mean age of 36.

Localized Fibrous Mesothelioma

Localized fibrous mesothelioma is the last benign form of mesothelioma. It is also called “benign fibrous mesothelioma.”

This benign cancer is most common in the pleura (lining of the lung cavity). Men and women have an equal chance of getting this disease.

There are malignant forms of fibrous mesothelioma. However, they are very rare. Long-term survival is possible with swift and effective treatment.

The most common symptoms of localized fibrous mesothelioma are:

  • Chest pain
  • Pleural effusions
  • Coughing
  • Shortness of breath

Sources & Author

Devin Golden

About the Writer, Devin Golden

Devin Golden is a content writer for Mesothelioma Guide. He produces mesothelioma-related content on various mediums, including the Mesothelioma Guide website and social media channels. Devin's objective is to translate complex information regarding mesothelioma into informative, easily absorbable content to help patients and their loved ones.