Mesothelioma

10 Apr

WHAT IS MESOTHELIOMA?

     Mesothelioma is a type of cancer which also known to its popular name “malignant mesothelioma. It is a rare form of cancer that develops from the cell of mesothelium.

Mesothelium is the protective lining which covers many of the internal organs of the human’s body. Mesothelioma is most commonly caused by exposure to asbestos.
Mesothelioma, a cancer that is directly traceable to repeated or long-term exposure to asbestos. The disease gets its name because of cancerous tumors form in the mesothelium (the lining of an internal organ). In the case of mesothelioma, the tumors form in the lining of the lung, the lining of the abdomen, the lining of heart or the lining of testicle.

WHAT IS ASBESTOS? 

     Asbestos is a set of six naturally occurring silicate minerals used commercially for their desirable physical properties.  Asbestos became increasingly popular among manufacturers and builders in the late 19th century because of its sounds absorption, average tensile strength, its resistance to fire, electrical, heat and chemical damage and affordability. It was used in such application as electrical insulation for hotplate wiring and building insulation. When asbestos is used for its resistance to fire or heat, the fiber are often mixed with cement (resulting in fiber cement) or women into fabric or mats.

Pleura is the most common anatomical site for mesothelioma. In Human anatomy pleura is the outer lining of the lung and and internal chest wall. Pleura is a serous membrane which folds back into itself to formed two-layered membrane structure.

The thin space between the two pleural layer is known as the pleural cavity and normally contain a small amount of pleural fluid.

The outer pleura which is known as parietal pleura is attached to the chest wall. The inner pleura which is known as visceral pleura covers the lungs and adjoining structures, through the blood vessels, bronchi and nerves.

The parietal pleura is high sensitive to pain, while the visceral pleura is not, due to its lack of sensory.

Mesothelioma can also arise in the peritoneum, the lining of the abdominal cavity. It can also arise in pericardium, the sac that surrounds the heart,  or in the tunica vaginalis, the sac that surrounds the testis.


WHAT IS PERITONEUM?

    Peritoneum is the serous membrane that forms the lining of the abdominal cavity or the coelom– It covers most of the intra-abdominal or what we call coelomic organs. Peritoneum is composed of a layer of mesothelium supported by a thin layer of connective tissue. The peritoneum both supports the abdominal organs and serves as a conduit for their blood and lymph vessels and nerves.

WHAT IS PERICARDIUM?

     Is a doubled walled sac containing the heart and the roots of great vessels. Pericardium is a tough doubled membrane which covers the heart. The space between the two layers of it is filled with a pericardium fluid which protects the heart from any kind of external jerk or shock. Pericardial sac has two layers which is the outermost fibrous pericardium and the inner serous pericardium. The serous pericardium, in turn, is divided into two layers, the parietal pericardium, which is fused to and inseparable from the fibrous pericardium and the visceral pericardium, which is part of the epicardium.

The epicardium is the layer immediately outside of the heart muscle proper the myocardium.

The visceral layer extends to the beginning of the great vessels, becoming one with the parietal layer of the serous pericardium. This happens at two areas, where the aorta and the pulmonary trunk leave the heart and where the superior vena cava, interior vena cava, and pulmonary veins enter the heart.



WHAT IS TUNICA VAGINALIS?

     Tunica vaginalis is the serous covering of the testis. It is a pouch of the serous membrane, derived from the processus vaginalis of theperitoneum, which in the fetus preceded the descent of the testis from the abdomen into the scrotum.
After its descent, that portion of the pouch which extends from the abdominal inguinal ring to near the upper part of the plan becomes obliterated, the lower  portion remains as a shut sav, which invests the surface of the testis, and is reglected on the internal surface of the scrotum, hence it may be described as a consisting of the visceral and a parietal lamina.
Most people who develop mesothelioma have worked in the jobs where they inhaled or ingested asbestos fibers, or were exposed to airborne asbestos dust and fibers in other ways. It as also been suggested that washing clothes of a family member who worked with asbestos increases their risk for developing mesothelioma. Unlike lung cancer, there seems to be no association between mesothelioma and tobacco smoking, but smoking greatly increases the risk of other asbestos induced cancers/ Some people who were exposed to asbestos have collected damages for asbestos-related disease, including mesothelioma, Compensation through asbestos funds or class action lawsuits is an important issue in law practices regarding mesothelioma. 
Malignant mesothelioma is a cancer that starts in the cells that line certain parts of the body, especially the chest and belly or abdomen. The lining formed by these cells is called mesothelium. These cells protect organs by making a special fluid that allows the organs to move. For instance, this fluid makes it easier for the lungs to move breathing.

TYPES OF MESOTHELIOMA
  1. Pleural mesotheliomas – start in the chest. They account for about 3 out of 4 mesotheliomas
  2. Peritoneal mesotheliomas – begins in the abdomen. They make up most of the remaining cases.
  3. Pericardial mesotheliomas – Starts in the covering around the heart and are very rare.
  4. Mesotheliomas of the tunica vaginalis – are very rare tumors that start in the layer around the testicles.
Mesotheliomas can also be grouped based on how the cancer cells look under a microscope.

  • Epitheloid – This is the most common type, it tends to have a better outlook than the other types.
  • Sarcomatoid (fibrous) – About 1 to 2 our of 10 mesotheliomas are of this type.
  • Mixed (biphasic) – This type has features of the 2 types above. About 3 to 4 mesotheliomas are the mixed type.

SIGNS AND SYMPTOMS OF MESOTHELIOMA
     Signs and symptoms of mesothelioma may not appear until 20 to 50 years or ever more after exposure to asbestos.

Signs and symptoms of Pleural Mesothelioma:
  • Shortness of breath
  • cough
  • pain in the chest due to an accumulation of fluid in the pleural space (pleural effusion)

Signs and symptoms of Peritoneal Mesothelioma
  • Weight loss
  • Cachexia
  • Abdominal swelling
  • Pain due to ascites (a buildup of fuid in the abdominal cavity)
  • Bowel obstruction
  • Blood clotting abnormallites
  • Anemia
  • Fever
  • Trouble swallowng
  • Swelling of the neck or face
OTHER SIGNS AND SYMPTOMS OF MESOTHELIOMA
  • Chest wall pain
  • Pleural effusion, or fluid surrounding the lung
  • shortness of breath
  • Fatigue or anemia
  • Wheezing, hoarseness, or cough
  • Blood in the sputum (fluid) coughed up (hemoptysis)
  • Abdominal pain
  • Ascites, or an abdominal buildup of fluid in the abdomen
  • A mass in the abdomen
  • Problems with bowel function
  • Weight loss
  • Blood clots in the veins, which may cause thrombophiebitis
  • Disseminated Intravascular coagulation, a disorder causing severe bleeding in many body organs
  • Jaundice, or yellowing of the eyes and skin
  • Low blood sugar level
  • Pleural effusion
  • Pulmonary emboil, or blood clots in the arteries of the lungs
  • Severe ascities
Pleural tumors are usually found only on the side of the lungs, Mesothelioma does not usually spread to the bone, brain or adrenal glands.

CAUSES OF MESOTHELIOMA

     Working with asbestos is the major risk factor for mesothelioma. In the United States , asbestos is the major cause of malignant mesothelioma and has been considered indisputably associated with the development of mesothelioma. The relationship between asbestos and mesothelioma is so strong that many consider a mesothelioma a “signal or sentinel”.

People believed to be in the high risk category for getting mesothelioma are those are were exposed to asbestos on a regular bases (six months or more while on the job. Among the list of occupations closely linked to mesothelioma and other asbestos-related diseases are:

  • Military veterans (especially the U.S. Navy)
  • Construction workers
  • Demolition or renovation crews
  • Auto mechanics
  • Insulators
  • Shipyard workers
  • Asbestos mine workers or millers
  • Boilers workers
  • Asbestos manufacturing plant workers

Environmental Exposures – Incidence of mesothelioma had been found to be higher in populations living near naturally occurring asbestos.

Occupational – Exposure to asbestos fibers has been recognized as an occupational health hazard since the early 20th century. Numerous epidemiological studies have associated occupational exposure to asbestos with the development of pleural plaques, diffuse pleural thickening, asbestoses, carcinoma of the lung and larnyx, gastrointestinal tumors, and diffuse malignant mesothelioma of the pleura and peritoneum. Asbestos has been widely used in many industrial products, including cement, brake lining, gaskets, roof shingles, flooring products, textiles, and insulation. 

Commercial asbestos mining at Wittenoom, Western Australia, occurred between 1945 and 1966. A cohort study of miners employed at the mine reported that while no deaths occurred within the first 10 years after crocidolite exposure., 85 deaths attributable to mesothelioma had occurred by 1985. By 1994, 539 reported deaths due to mesothelioma had been reported in Western Australia.
Paraoccupational Secondary Exposure – Family members and other living with asbestos workers have an increased risk of developing mesothelioma and possibly other asbestos related diseases.
Asbestos in Buildings – Many building materials used in both public and domestic premises prior to the banning of asbestos may contain asbestos. Those performing renovation works or DIY activities may expose themselves to asbestos dust. 

References:


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One Response to “Mesothelioma”

  1. Mesothelial Cells June 19, 2013 at 9:37 am #

    I am actually glad to glance at this web site posts which includes lots
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