Malignant Pleural Mesothelioma – Asbestos

Malignant Pleural Mesothelioma - Asbestos Exposure

Note: Don’t miss to watch the video following after this article to learn further and have a better insight about malignant pleural mesothelioma. The video is very informative and helps you learn “these big words” that medical books/studies and doctors are using.

Dr. Raja Flores, from Memorial Sloan-Kettering Cancer Center, gives the best explanation in the video about malignant pleural mesothelioma. He said: “In medicine we try to make ourselves seem really smart. So we use these big words that people frequently cannot understand… So every once in a while you’ll come across these big words that we use and they just mean simple things. But we’re trying to confuse people because it makes us feel as if that we’re a little bit smarter.” . . .The following information/excerpts are taken from Merck Manual and and Currrent Medical Diagnosis and Treatment books.

Pleural mesothelioma is the only known pleural malignancy and is caused by asbestos exposure in nearly all cases. Asbestos workers have up to a 10% lifetime risk of developing the disease, with an average latency of 30 year. Risk is independent of smoking.

Mesothelioma can spread locally or metastasize to the pericardium, diaphragm, peritoneum, and rarely, the tunica vaginalis of the testis.

Patients most often present with dyspnea and nonpleuritic chest pain… Invasion of the chest wall and other adjacent structures may cause severe pain, hoarseness, dysphagia, Horner’s syndrome, brachial plexopathy, or ascites. Extra thoracic spread occurs in up to 80% of patients, most commonly including the hilar and mediastinal lymph nodes, liver, adrenals, and kidneys.¹

Signs and Symptoms

The mean age at onset of symptoms of malignant pleural mesothelioma is about 60 years. Symptoms include the insidious onset of shortness of breath, nonpleuritic chest pain, and weight loss. Physical findings include dullness to percussion, diminished breath sound and, in some cases, digital clubbing.

Laboratory Findings and Diagnosis

Pleural fluid is exudative and often hemorrhagic. VATS biopsy is usually necessary to obtain an adequate specimen for histologic diagnosis; even then distinction from benign inflammatory conditions and from metastatic adenocarcinoma may be difficult. The histologic variants of malignant pleural mesothelioma are epithelial and fibrous (sarcomatous). Special stains and electron microscopy may be needed to confirm the diagnosis.

Imaging

Radiographic abnormalities consist of nodular, irregular, unilateral pleural thickening and varying degrees of unilateral pleural effusion. There may be scoliosis toward the side of the lesion. CT scan helps demonstrate the extent of pleural involvement. ²

Watch the video for a better understanding on malignant pleural mesothelioma. Dr. Raja Flores, from Memorial Sloan-Kettering Cancer Center gives the best explanation about malignant pleural mesothelioma.

Watch the next video with Dr. Raja Flores on this article: Malignant Pleural Mesothelioma: Complications, Treatment and Prognosis

¹ The Merck Manual, 18th edition, p. 471
² 2009 Current Medical Diagnosis and Treatment, p. 1435

Complications

Malignant Pleural Mesothelioma

Malignant pleural mesothelioma progresses rapidly as the tumor spreads along the pleural surface to involve the pericardium, mediastinum, and contralateral pleura. The tumor may eventually extend beyond the thorax to involve abdominal lymph nodes and organs. Progressive pain and dyspnea are characteristic.

Local invasion of thoracic structures may cause superior vena cava syndrome, hoarseness, Horner syndrome, and dysphagia.

Paraneoplastic syndromes associated with mesothelioma include thrombocytosis, hemolytic anemia, disseminated intravascular coagulopathy, and migratory thrombophlebitis.

Treatment -- Surgery, Radiotherapy and Chemotherapy

Treatment with surgery, radiotherapy, chemotherapy, and a combination of methods has been attempted but is generally unsuccessful. Some surgeons believe that extrapleural pneumonectomy is the preferred surgical approach for patients with early stage disease. Drainage of pleural effusions, pleurodesis, radiation therapy and even surgical resection may offer palliative benefit in some patients.

Note: Watch the video below and learn the best options available for you if you have malignant pleural mesothelioma. . . Don’t miss to watch this video — it’s very educational for both patients and physicians.

Prognosis

Most patients die of respiratory failure and complications of local extension. Median survival time from onset of symptoms ranges from 4 months in extensive disease to 16 months in localized disease. Five-year survival is less than 5%.

Source: Current Medical Diagnosis and Treatment, p. 1435

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