The 4 Types of Mesothelioma

Some of the internal organs or sections of the body, specifically the lungs, heart, abdomen, and testicles are covered by a membrane called mesothelium.

In addition to protecting the organs, the mesothelium increases mobility; for example, it enables the lungs to expand and retract, or the heart to pump more efficiently. Mesothelioma occurs when malignant tumors begin to develop in the mesothelium.

A rare form of cancer, mesothelioma is usually caused by exposure to asbestos, a fire-resistant material that was once widely used in the building, manufacturing, and mining sectors. There are four types of the disease: pleural, peritoneal, pericardial and testicular mesothelioma.

Small cell lung carcinoma simulating mesothelioma
Small cell lung carcinoma simulating mesothelioma (Photo credit: Pulmonary Pathology)

PLEURAL MESOTHELIOMA

Pleural mesothelioma is the most common form of this cancer. It accounts for about 75 percent of all cases in the US. It is named after the pleura, the dual-layered membrane that lines the inner and outer side of the pleural cavity, which contains the lungs and the heart.

The outer pleura, also known as the parietal pleura, line the chest wall. The inner pleura, or visceral pleura, protect the lungs. The most common symptoms of pleural mesothelioma are shortness of breath, persistent dry cough and chest pain, difficulty in swallowing food, fatigue, and night sweats or high fever.

Since there is no cure for the disease, treatment is merely implemented to alleviate the symptoms; palliative care can include chemotherapy, surgery, oxygen exercises and pain medications.

PERITONEAL MESOTHELIOMA

The second-most common type of mesothelioma is peritoneal mesothelioma, which accounts for about 20 percent of all US cases. Peritoneal mesothelioma is named after the peritoneum, the type of mesothelium that lines the abdomen. The peritoneum protects the organs in the abdomen, and it functions as a conduit for their nerves and vessels.

Thus, the defining symptoms of peritoneal mesothelioma affect the abdomen. With the tumors thickening the peritoneum and causing fluid build-up, sufferers tend to experience pain and swelling in that area. Other symptoms include fatigue, weight loss, nausea, vomiting, constipation, and diarrhea. Peritoneal mesothelioma metastasizes quicker than other forms of the disease, which makes treatment very difficult.

PERICARDIAL MESOTHELIOMA

Pericardial mesothelioma is one of the more rare forms of mesothelioma, only making up 5 percent of the cases in the US. This variant affects the pericardium, which is the exterior lining of the heart.

Fluid builds up in the spaces between the membrane’s layers and triggers symptoms that include an irregular heartbeat, chest pain, coughing, and labored breathing. Although pericardial mesothelioma can be treated like other forms of the cancer, surgery is usually avoided because of the proximity of the tumors to the heart.

TESTICULAR MESOTHELIOMA

Less than one percent of all mesothelioma cases are testicular mesothelioma, making it the rarest of the four variants. Testicular mesothelioma concerns the lining of the male reproductive organs (testicles), called the tunica vaginalis.

This type of mesothelioma is so rare that it has been difficult to come up with a comprehensive list of symptoms. Testicular mesothelioma is usually diagnosed with the appearance of lumps on the testicle or a swelling of the scrotum. Treatment usually involves removing a part, or the entire, affected organ. In some cases, physicians use chemotherapy or radiation therapy to get rid of the remaining tumors.

This article was written by nurse practitioner Laura Green.  Laura wants to share her love and knowledge of medicine with the community.