Benign Mesothelioma Tumor Types

The American Cancer Society explains that it is important for patients to recognize the differences between malignant and benign tumors, both of which begin in the mesothelium.  Although patient prognosis is generally favorable for patients with a benign tumor, prompt treatment is recommended. Even with treatment, benign tumors may return in about 10 percent of cases, with a recurrence period that can be as long as 10 years. These tumors require surgery to remove them, and additional treatment is generally not needed. Other names for benign mesothelioma include:

  • Mesothelioma – benign
  • Mesothelioma – fibrous
  • Localized fibrous tumor of the pleura
  • Pleural fibroma

Tumor Types

Adenomatoid tumor

This type of benign tumor may develop in the mesothelium, a protective tissue, of reproductive organs of both men and women. When seen in women, this tumor may start developing in the fallopian tubes, which carry eggs from the ovaries to the uterus. In men, this tumor types generally begins in the epididymis, which is a tiny collection of ducts that serve to carry sperm cells out of the testicle.

Benign cystic mesothelioma

This benign tumor may also begin in the mesothelium near women’s reproductive organs. Peroperative diagnosis of this disease is difficult but information provided by computer tomography and cytology may help. While those tests may provide insight, a firm diagnosis can only be confirmed from electron mircoscopic or immunohistochemical examination of the tumor.

Solitary fibrous tumor of the pleura

Developing in the pleura surrounding the lungs, this tumor was once known to doctors as benign fibrous mesothelioma. However, doctors changed its name after learning that this tumor does not start in mesothelial cells, but in tissue under the mesothelium. Though this form of tumor is generally benign, about ten percent of cases are cancerous. Solitary Fibrous tumor of the peritoneum is a similar disease which begins in the peritoneum.


The American Cancer Society

U.S. National Library of Medicine