Resources for Patients and their Families

Benign Mesothelioma

Benign mesothelioma comes in many different forms, all of which are non-cancerous. Surgery is required to remove the benign tumors, though treatment is generally easier than with malignant mesothelioma and life expectancy is not affected. Benign mesothelioma can recur, with a potential to be malignant.

Asbestos is a proven cause for malignant mesothelioma, but the cause of benign mesothelioma is unknown. There doesn’t seem to be a connection with asbestos, though more evidence and research is needed to understand any correlation with the disease.

Types of Benign Mesothelioma

Benign mesothelioma is extremely rare, but it can present in different types, such as benign multicystic peritoneal mesothelioma (BMPM), well-differentiated papillary mesothelioma (WDPM), adenomatoid tumors (AT), and localized fibrous tumors (LFT). Each type differs based on location, symptoms, and other factors.

Although some symptoms may be characteristic of a particular type of benign mesothelioma, many times symptoms mimic those of malignant. There are three main types of mesothelioma with prominent symptoms, including malignant pleural mesothelioma, peritoneal mesothelioma, and pericardial mesothelioma.

Benign Multicystic Peritoneal Mesothelioma

BMPM is a benign form of mesothelioma that can occur in both men and women, though is most common in women of reproductive age. Women who have had abdominal surgery, endometriosis, or pelvic inflammatory disease in the past are more susceptible to developing the disease. There is a high rate of recurrence with this form of benign cystic mesothelioma, with around 50% of cases seeing recurring mesothelioma tumors 1 – 27 years after diagnosis. There is the potential for tumors to come back as malignant.
Location: wall linings of the abdomen (peritoneal mesothelium)
Symptoms: pelvic or abdominal pain, tenderness, constipation, urinary hesitancy

Well-Differentiated Papillary Mesothelioma

WDPM is an uncommon, non-cancerous tumor typically found in women. A recent study found WDPM has a low rate of recurrence, but more information is needed as confirmation. In many cases, there were no symptoms, though some patients did exhibit negative side effects.
Location: most common within the abdominal cavity (peritoneum), though occasionally develops within the membrane surrounding the heart (pericardium), lung linings (pleura), and testicular linings (tunica vaginalis)
Symptoms: pelvic or abdominal pain, swelling

Adenomatoid Tumors

AT is slow-growing and non-cancerous, affecting both men and women, though most cases are found in middle-aged or older women. Adenomatoid mesothelioma tumors are often found accidentally, which complicates early diagnoses. However, as a benign form of mesothelioma, treatment is usually curative with no hindrance to lifespan.
Location: testicular linings, uterus wall, fallopian tube, and other reproductive organs
Symptoms: usually asymptomatic

Localized Fibrous Tumor (LFT)

Rare and benign, localized fibrous tumors equally affect both men and women. Recurrence is possible with fibrous mesothelioma, and while around half of reported cases have experienced no symptoms, the other half did experience bothersome effects.
Location: lung linings (most common), lining of the heart, testicular linings, or abdominal cavity (less common)
Symptoms: Asymptomatic or thoracic pain, fever, difficulty breathing, weight loss

Diagnosis of Benign Mesothelioma

Any recognition of symptoms should be brought to a physician’s attention immediately. The doctor will look at patient’s history and symptoms, and will also conduct a variety of testing to determine whether or not the patient has mesothelioma, if it is malignant or benign, and what type of mesothelioma he or she has.

Image Testing: There are three main types of imaging tests that are used on the path to diagnosis. Chest X-Rays, CT scans, and MRIs are all used to help determine tumor location and size.

Biopsies: A biopsy is the only definitive way to diagnose mesothelioma. There are three main types of biopsies commonly used, including a needle biopsy, camera-assisted biopsy, and surgical biopsy. Analysis of cancer cells can help doctors determine cell type and therefore, the best treatment options available for the patient.

Main Differences Between Malignant and Benign Mesothelioma

As noted through their names, the main difference between malignant mesothelioma and benign mesothelioma is that the first is cancerous, while the latter is non-cancerous. Upon diagnosis, doctors will help explain the difference between benign and malignant, helping to outline the difference of treatment options, life expectancy, and symptoms.

Metastasis by Peritoneal Mesothelioma Stage Comparison of Mesothelioma Types
Malignant Mesothelioma Benign Mesothelioma
Common Treatments: Surgery, chemotherapy and radiation, combination of treatments (multimodal), and palliative Common Treatments: Surgery (curative) with high success rate
Metastasis: Aggressive growth, possible recurrence Metastasis: No metastasis, possible recurrence
Life Expectancy: 12 - 21 months on average Life Expectancy: Generally unaffected
Organ and Tissue Damage: Frequently causes damage to healthy tissues and organs at point of origin and sometimes nearby tissues Organ and Tissue Damage: Typically no damage

Benign Mesothelioma Treatment

There is currently no cure for the malignant form of mesothelioma, and life expectancy is bleak. Researchers and health care professionals are striving to find a cure for the disease and raise awareness towards mesothelioma and its known cause, asbestos exposure.

Benign mesothelioma is generally easy to treat with curative surgery to remove the tumor for a full, unaffected life afterwards. However, especially for some types of benign mesothelioma, recurrence can form malignant tumors. Patients that have been diagnosed with any type of benign mesothelioma typically undergo long-term monitoring and follow-ups. If patients experience bothersome symptoms from their benign tumor or post-surgery symptoms, palliative treatment is also an option to improve and maintain a high quality of life.

Understanding Rare Types of Mesothelioma

Benign mesothelioma is rare, and can often go misdiagnosed. Misdiagnosis is a common problem for rare diseases, making it important for patients to recognize and address any potential symptoms. Read more about malignant mesothelioma and other rare types to understand all potential symptoms.

Author: Linda Molinari

Editor in Chief, Mesothelioma Cancer Alliance

Linda Molinari

Bakhshi GD, Wankhede KR, Tayade MB, et al. Retroperitoneal Approach for Recurrent Benign Multicystic Peritoneal Mesothelioma. Clinics and Practice. 2013;3(1). doi:10.4081/cp.2013.e3.

Malpica A, Sant’Ambrogio S, Deavers MT, et al. Well-differentiated papillary mesothelioma of the female peritoneum: a clinicopathologic study of 26 cases. The American Journal of Surgical Pathology. 2012;36(1): 117-127. doi:10.1097/PAS.0b013e3182354a79.

National Center for Advancing Translational Sciences. Benign multicystic peritoneal mesothelioma. Genetic and Rare Diseases Information Center. 2011.

Sangoi AR, McKenney JK, Schwartz EJ, et al. Adenomatoid tumors of the female and male genital tracts: a clinicopathological and immunohistochemical study of 44 cases. Modern Pathology. 2009;22: 1228-1235. doi:10.1038/modpathol.2009.90.

Hohenforst-Schmidt W, Grapatsas K, Dahm M, et al. Solitary fibrous tumor: A center’s experience and an overview of the symptomatology, the diagnostic and therapeutic procedures of this rare tumor. Respiratory Medicine Case Reports. 2017;21: 99-104. doi:10.1016/j.rmcr.2017.04.007.

Mesothelioma Treatment Guide

Free Mesothelioma Treatment Guide

Please fill in the form below to request our FREE Mesothelioma Treatment Guide. It will be sent to you within 24 hours.

Have you or someone you know been diagnosed with mesothelioma?

Get Access To: