Epidemiolgy:
Erin
The estimated number of new cases of malignant mesothelioma in the United States is approximately 2,000-3,000 per year.1 The median age at time of diagnosis is 72-74 years. Most patients with mesothelioma probably had an initial exposure to carcinogens (asbestos) about 40 years prior to diagnosis. However, it is thought that the peak incidence of cases in the U.S. occurred in 2008. In other countries, it may still be on the rise because implementation of asbestos restrictions occurred later in many other countries than it did in the U.S. About 80% of patients who are diagnosed with mesothelioma are males.
Etiology:
Spencer
Although very little is known about what causes pleural cancers, there are a few possible things that make a person more likely to develop a tumor.2
  • One of the possible underlying causes of this disease is from complications with mesothelioma, or asbestos exposure.
  • Smoking
Signs & Symptoms:
Pablo
Pleura cancers
This type of cancer can either be a primary as in the case of mesothelioma, or cancer from a primary like lung cancer that has spread into the lining of the lungs. In general the patient presents with any of the following symptoms:
  • Loss of appetite
  • Pleural effusion
  • Shortness of breath
  • Difficulty breathing and or sleeping
  • Weight loss
  • Chronic cough3
Diagnostic Procedures:
Becky
Diagnostic procedures to detect abnormalities of the pleura of the lung are:4
  • Chest x-rays
  • Computed Tomography (CT) scan
  • Magnetic Resonance Imaging (MRI)
  • Positron emission tomography (PET) scan
  • Fine needle aspiration
  • Lab test
Histology:
Adam
The pleura is made up of mesothelial cells and vascularized connective tissue, which gives it a smooth surface ideal for facilitating the motion from the heart and lungs.5
Lymph node drainage:
Megan
lymph-nodes-of-pulmonary-system.gif
Metastatic spread:
Kevin Tsai
  • Mesothelioma is a aggressive cancer because it grows quickly and spreads to other parts of the body within a matter of months6
  • It usually develops in the chest cavity or the abdominal cavity and affects vital organs like the lungs and heart (local spread)
  • It travels much quicker than other types of cancer because it is located near the lungs, which transfer oxygen throughout the body. Therefore, mesothelioma cells may be able to enter the bloodstream and circulate through the body
  • Known to metastasize to the spine, brain, prostate, retroperitoneal lymph nodes, and thyroid
Grading:
Erin
Not much information exists on the grading of malignant pleural mesotheliomas. Since the prognosis overall is poor, they are not commonly graded.7 The differences in behavior and prognosis of different histology tumors are minimal, therefore distinctions between what could be classified as low-grade or high-grade has little clinical significance.
Staging:
Spencer
American Joint Committee on Cancer Staging System for Pleural Cancers.8
Malignant Pleural Mesothelioma Cancer Staging
TNM

Primary Tumor (T)
TX – Primary tumor cannot be assessed.
T0 – There is no evidence of the primary tumor.
T1a – There is no involvement of visceral pleura.
T1b – The tumor is involved with the visceral pleura.
T2 – Tumor involves the pleural lining of the chest wall on one side of the chest, as well as the pleural lining of the diaphragm and mediastinum.
T3 – Considered advanced, but still may be able to surgically remove the tumor. Involves the pleural lining of the chest wall and pleural lining of the lung, diaphragm, and mediastinum.
T4 – Considered unresectable. The tumor involves the pleural lining of the chest wall and the pleural lining of the lung, diaphragm, and mediastinum on one side of the chest.

Regional Lymph Nodes (N)
NX – Regional lymph nodes that cannot be assessed.
N0 – No regional lymph node spread.
N1 – Spread to the ipsilateral bronchopulmonary or hilar lymph nodes
N2 – Spread to the subcarinal or ipsilateral mediastinal lymph nodes.
N3 – Spread to the contralateral mediastinum, internal mammary, and supraclavicular lymph nodes.

Distant Metastasis (M)
M0 – No distant metastasis present.
M1 – Distant metastasis.

pleura stage.jpg
Radiation side effects:
Pablo
The side effects experienced by the administration of radiotherapy can vary depending on the general health of the patient, but most patients can experience the following:
  • Fatigue
  • Radiation pneumonitis
  • Pericarditis
  • Radiation dermatitis
  • Pericardial tamponade9
Prognosis:
Becky
Prognosis for mesothelioma is generally poor, typically 1 to 2 years after diagnosis. This doesn’t mean there isn’t an exception to the overall prognosis. Depending on the general health of the patient, type, location, stage and if metastases is present, are factors to be considered when talking about prognosis.4
Treatments:
Adam
  • Surgery - Pneumonectomy and extrapleural pneumonectomy are both surgical options for treating mesotheliomas that have no metastasized.11
  • Chemotherapy - The most common treatment. A combination of alimta and cisplatin is currently the only approved chemo drug combination by the FDA.11
  • Radiation Therapy - Usually used as an adjuvant therapy to surgery and chemotherapy, either through external beam or brachytherapy. Radiation therapy may also be used alone in palliative cases.11
TD 5/5:
Megan
Pleura TD 5-5.JPG
References:
  1. Medscape News Today. Malignant Pleural Mesothelioma. http://www.medscape.com/viewarticle/759119_2. Accessed June 13, 2013.
  2. Pleural Tumors. University of Rochester Medical Center Web Site. http://www.urmc.rochester.edu/encyclopedia/content.aspx?ContentTypeID=22&ContentID=PleuralTumors. Accessed on June 11, 2013.
  3. Mesothelioma-Net. Web site. http://www.mesothelioma-net.org/information/pleural-mesothelioma/?kw=mesothelioma&c=google&gclid=CL2ho53A2rcCFcFj7AodchgA2Q. Accessed Jun 10, 2013.
  4. Mesothelioma prognosis. Mesothelioma Web Site. http://www.mesothelioma.com/mesothelioma/prognosis Accessed June 11, 2013.
  5. Pleura. Pathology Outlines Web Site. http://www.pathologyoutlines.com/pleura.html. 2011. Accessed June 13, 2013.
  6. CureASPS.org website. Cure Alveolar Soft Part Sarcoma International (iCureASPS). http://cureasps.org/forum/viewtopic.php?p=2803. Modified November 4, 2010. Accessed June 8, 2013.
  7. Mesothelioma Metastasis. Asbestos Web site. http://www.asbestos.com/mesothelioma/metastasis.php. 2013. Accessed June 11, 2013.
  8. Cancer Grading Manual. Malignant Mesothelioma. http://books.google.com/books?id=fbDC_GtE5bYC&pg=PA29&lpg=PA29&dq=how+is+mesothelioma+graded?&source=bl&ots=Rk--sCdlbq&sig=0JgucSO4KYasXqSE5H_ckGXlDU4&hl=en&sa=X&ei=ERq6UdyTM4XM9AS6y4GgBg&ved=0CEsQ6AEwAQ#v=onepage&q=how%20is%20mesothelioma%20graded%3F&f=false. Accessed June 13, 2013.
  9. Malignant Mesothelioma Treatment. National Cancer Institute Web Site. http://www.cancer.gov/cancertopics/pdq/treatment/malignantmesothelioma/HealthProfessional/page3. Accessed June 11, 2013.
  10. American Cancer Society. Web site. http://www.cancer.org/treatment/treatmentsandsideeffects/treatmenttypes/radiation/understandingradiationtherapyaguideforpatientsandfamilies/understanding-radiation-therapy-side-effects. Accessed Jun 10, 2013
  11. Mesothelioma Metastasis. Asbestos Web site. http://www.asbestos.com/mesothelioma/metastasis.php. 2013. Accessed June 11, 2013.
  12. Pleural Mesothelioma | Treatment, Prognosis, Diagnosis. Mesothelioma Web Site. http://www.mesothelioma.com/mesothelioma/types/pleural.htm. Accessed June 13, 2013.
  13. Singer JJ. The Lymphatic Drainage of the Pleura as Demonstrated by Thorotrast. Cal West Med. 1942 July; 57(1): 28–29. PMCID: PMC1634707
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