Malignant Pleural Mesothelioma – Asbestos

Numerous studies have confirmed the association of malignant pleural mesothelioma with exposure to asbestos

Mesotheliomas are primary tumors arising from the surface lining of the pleura (80% of cases) or peritoneum (20% of cases).

About three-fourths of pleural mesotheliomas are diffuse (usually malignant) tumors, and the remaining one-fourth are localized (usually benign). Men outnumber women by a 3:1 ratio.

Asbestos Exposure

Numerous studies have confirmed the association of malignant pleural mesothelioma with exposure to asbestos (particularly the crocidolite form). The lifetime risk to asbestos workers of developing malignant pleural mesothelioma is about 8%. Sixty to 80% of patients with malignant mesothelioma report a history of asbestos exposure. The latent period between exposure and onset of symptoms ranges from 20 to 40 years.

The clinician should inquire about asbestos exposure through mining, milling, manufacturing, shipyard work, insulation, brake linings, building construction and demolition, roofing materials, and a variety of asbestos products (pipe, textiles, paint, tile, gaskets, panels.

Cigarette Smoking Significance

Although cigarette smoking significantly increases the risk of bronchogenic carcinoma in asbestos workers and aggravates asbestosis, there is no association between smoking and mesothelioma.

Source: Current Medical Diagnosis and Treatment, p. 1435

Before knowing about malignant pleural mesothelioma let’s learn first what are  mesothelium, mesothelioma and other related terms.

As I was reading about mesothelioma I had encountered some terms such as peritoneal, pericadium, and pleura, etc. These terms were confusing me. Last week we went to the library and I had found a couple of books about mesothelioma.

What is the mesothelium?

The mesothelium is a membrane that covers and protects most of the internal organs of the body. The mesothelium consist of 2 layers of cells:

• one layer immediately surrounds the organ;
• the other layer forms a sac around it.

The mesothelium produces a lubricating fluid that is released between these layers so that the organs can move and glide easily such as:

• the beating heart and,
• the expanding and contracting of lungs

The mesothelium has different names, depending on it’s location in the body.

Pleural mesothelioma starts in pleura, or lining of the chest outside the lung

• The peritoneum is the mesothelial tissue that covers most of the organs in the abdominal cavity.
• The pleura is the membrane that surrounds the lungs and lines the wall of the chest cavity.
• The pericardium covers and protects the heart.
• The mesothelial tissue surrounding the male internal reproductive organs is called the tunica vaginalis testis. The tunica serosa uteri covers the internal reproductive organs in women.

What is mesothelioma?

Mesothelioma is a rare form of cancer in which malignant (cancerous) cells are found in the mesothelium, a protective sac that covers most of the body’s internal organs. Most people who develop mesothelioma have worked on jobs where they inhaled asbestos particles.

Mesothelioma (cancer of the mesothelium) is a disease in which cells of the mesothelium become abnormal and divide without control or order. They can invade and damage nearby tissues and organs. Cancer cells can also metastasize (spread) from their original site to other parts of the body.

Most cases of mesothelioma begin inside the chest, in the pleural membranes surrounding the lungs. Rarely, it may develop inside the abdominal cavity. It is possible for the cancer to arise in other locations, but this is extremely rare. ¹

Symptoms of mesothelioma may not appear for decades after the initial asbestos exposure.

Helpful Online Searches Related to Malignant Pleural Mesothelioma

• Conditions:
  • lung cancer
  • tumor
  • asbestosis
  • adenocarcinoma
  • breast cancer
  • carcinoma
  • lymphoma
• Symptoms
  • weight loss
  • chest pain
  • cough
  • back pain
  • angina
  • fatigue
  • diarrhea
  • abdominal pain

¹ Source: Respiratory Disorders SourceBook, p. 479-480