Understanding Different Types of Mesothelioma

Author: Cates Law
Mesothelioma is a deadly form of cancer that affects the mesothelium, the protective lining which covers the body's internal organs. Mesothelioma diagnoses average approximately 2,500 to 3,000 new cases a year. This is roughly 3% of all new cancer diagnoses, and this number is expected to rise until at least 2025. Mesothelioma, as a result of the exposure methodology, primarily affects men who were employed in trades, and is an incurable, or terminal, disease. It can, in certain cases, be managed, however, depending the timing of diagnosis and the aggressiveness of the treatment. Exposure to asbestos is the major risk-factor for the development of this disease, and is the only known cause of mesothelioma in the United States.
Typically, mesothelioma is found affecting the lining of the lungs (pleural mesothelioma), the lining of the heart, (pericardial mesothelioma), or the lining of other abdominal organs (peritoneal mesothelioma). In addition to these three main types, there have been rare cases of mesothelioma which affect the testicles (testicular mesothelioma). There is also benign mtyesothelioma, which is not fatal.
Pleural MesotheliomaThe pleura is the name for the protective lining of the lungs. Pleural Mesothelioma is a cancer that establishes itself in that lining. This is by far the most common type of mesothelioma, and it accounts for over 70% of all malignant mesothelioma diagnoses.
The pleura are a serous membrane, not unlike the peritoneum. The pleura is a continuous membrane, that wraps around the lungs for protection and support, and then folds back over on itself, creating a small cavity between the upper and lower layers. This cavity between the layers is often referred to as the pleural cavity. The pleural cavity typically contains pleural fluid. The outer pleuron, which is attached to the chest wall, is called the parietal pleura. The inner pleuron, which wraps itself around the lungs, blood vessels to and from the lungs, nerves and bronchi, is called the visceral pleura. It should be noted that the parietal pleura (outer pleura) is attached to nerves (innervated) and thus is capable of pain sensation, while the visceral pleura is not.
Mesothelioma which affects the pleura can often lead to effusions. As noted, the pleura have a small cavity between the parietal and visceral layer, which contains fluid. Mesothelioma can cause a buildup of fluids which are then forced out of the pleural cavity and into the chest cavity. This escape of the pleural fluid, from where it should normally be, is called a pleural effusion.
A pleural effusion can lead to physical pain, which is a symptom of mesothelioma. Other symptoms associated with pleural mesothelioma can be different than those associated with the peritoneal, pericardial, or testicular mesothelioma. This is due to the differing location of the affected area. Commonly reported symptoms of patients diagnosed with pleural mesothelioma include:
  • Chest Pain
  • Chest Swelling
  • Coughing Fits
  • Dry Coughs
  • Effusions (leaking of fluid into body cavity)
  • Generalized Weakness / Fatigue
  • Lack of ability to breathe without pain
  • Loss of Appetite
  • Loss of Weight
  • Night Sweats
  • Visible / Palpable Lumps in the Chest
Not all patients diagnosed with pleural mesothelioma will experience all of these symptoms. Treatments may also differ depending on the Stage of the Cancer, its location, and how quickly the cancer was diagnosed.
For more on treatment options, please see Treatment of Mesothelioma
Pericardial Mesothelioma – The pericardium is the name for the protective tissue lining which surrounds and protects the heart. Pericardial mesothelioma is a cancer that establishes itself in the lining around the heart.
The pericardium is actually a sac of tissue, which houses the heart and the beginnings and ends, of the main blood vessels leading into and out of the heart. The pericardial sac is actually composed of two layers. There is the fibrous pericardium, and the serous pericardium. The serous pericardium is also composed of two layers. The first layer, the parietal pericardium, is attached to the fibrous pericardium. The parietal pericardium and the fibrous pericardium cannot be detached. The second layer is the visceral pericardium, which is adjacent to the heart itself. As with the pleura and pericardium, there is a small space between the parietal and visceral pericardium layers, which is usually filled with a lubricating, pericardial fluid. Mesothelioma of the pericardium can cause a buildup of this fluid, which can result in a pericardial effusion. This buildup of fluid caused by pericardial mesothelioma can also lead to a pericardial tampondae, where the heart is actually compressed inside the pericardium.
The symptoms associated with peritoneal mesothelioma can be different than those associated with the pleural, pericardial, or testicular mesothelioma. This is due to the differing location of the affected area. Commonly reported symptoms of patients diagnosed with peritoneal mesothelioma include:
  • Chest Pain
  • Chest Swelling
  • Chronic Nausea / Vomiting
  • Difficulty Breathing
  • Effusions (leaking of fluid into body cavity)
  • Generalized Weakness / Fatigue
  • Heart Murmurs
  • Heart Palpitations
  • Inability to catch your breath
  • Loss of Appetite
  • Loss of Weight
  • Persistent Cough
  • Sweating while Sleeping
Not all patients diagnosed with pericardial mesothelioma will experience all of these symptoms. Treatments may also differ depending on the Stage of the Cancer, its location, and how quickly the cancer was diagnosed.
Peritoneal Mesothelioma – The peritoneum is the name for the tissue lining, or membrane, which surrounds, supports and protects the abdominal cavity, and the organs therein. Peritoneal mesothelioma is a cancer of that lining. This is the second most common type of mesothelioma, accounting for approximately 20% of all mesothelioma diagnoses.
The peritoneum is actually comprised of two mesothelial layers. The upper layer, which is actually attached to the abdominal way, is called the parietal layer. The lower layer, which is the layer of membranous tissue surrounding the individual organs, is called the visceral layer. Peritoneal mesothelioma is the result of asbestos fibers collecting, and becoming lodged in-between the visceral and parietal layers.
Mesothelioma which affects the peritoneum can often lead to effusions. As noted, the peritoneum has a small cavity between the parietal and visceral layer, which contains fluid. Mesothelioma can cause a buildup of fluids which are then forced out of the peritoneal cavity and into the chest cavity. This escape of the peritoneal fluid, from where it should normally be, is called a peritoneal effusion.
The symptoms associated with peritoneal mesothelioma can be different than those associated with the pleural, pericardial, or testicular mesothelioma. This is due to the differing location of the affected area. Commonly reported symptoms of patients diagnosed with peritoneal mesothelioma include:
  • Abdominal Pain
  • Abdominal Swelling
  • Chronic Diarrhea / Constipation
  • Chronic Nausea / Vomiting
  • Effusions (leaking of fluid into body cavity)
  • Generalized Weakness / Fatigue
  • Generalized Pain in the Abdominal Area
  • Loss of Appetite
  • Loss of Weight
  • Night Sweats
  • Stomach Pain
  • Visible / Palpable Lumps on the Abdomen
Not all patients diagnosed with peritoneal mesothelioma will experience all of these symptoms. Treatments may also differ depending on the Stage of the Cancer, its location, and how quickly the cancer was diagnosed.
Testicular MesotheliomaTesticular mesothelioma establishes itself in the tunica vaginalis. The tunica vaginalis is a serous membrane which covers the testis. Like the other forms of mesothelioma, testicular mesothelioma is a cancer of the cells of that membrane. Though it is extremely rare, mesothelioma can develop in this lining, which will lead to generalized symptoms, such as:
  • Chronic Nausea / Vomiting
  • Effusions (leaking of fluid into body cavity)
  • Generalized Weakness / Fatigue
  • Groin Pain
  • Groin Swelling Loss of Appetite
  • Loss of Weight
  • Night Sweats
  • Visible / Palpable Lumps in the Groin
Not all patients diagnosed with testicular mesothelioma will experience all of these symptoms. Treatments may also differ depending on the Stage of the Cancer, its location, and how quickly the cancer was diagnosed.
Benign MesotheliomaBenign mesothelioma simply means that mesothelioma is indicated, but it is non-malignant and thus not a growing tumor and is not fatal.
Histologically, there are three types of malignant mesothelioma. This means that the actual types of cells which comprise the mesothelioma cancer have three types of organization. They include:
  • Epithelioid
  • Sarcomatoid
  • Biphasic (Mixed)
Approximately 50-60% of mesothelioma diagnoses involve the epithelioid type. Mesothelial cells are, by their nature and design, epithelial in shape. These cells are typically well-defined, and are recognizable for their uniform shape when viewed through a microscope. Due the resemblance that epithelial mesothelioma cells have to another common form of lung cancer, called an adenocarcinoma, it is not uncommon for doctors who not familiar with a patient's history of working around asbestos, to misdiagnose mesothelioma as adenocarcinoma. This is why it is important for a patient to ensure their doctor is informed of any asbestos exposure. A patient may also choose to seek a second opinion from a specialist in mesothelioma to ensure the proper diagnosis is made. The epithelioid type of mesothelioma cancer cells have a better long-term prognosis in similar patients than Sarcomatoid or Biphasic.
Sarcomatoid mesothelioma is found in approximately 10-20% of all mesothelioma diagnoses in a given year. This type can be difficult to diagnose because of its close microscopic resemblance to sarcomatoid carcinoma (another type of lung cancer). These cells are also often misconstrued as non-malignant fibrous tissue. The shape of a sarcomatoid cell is typically elongated, with spindle attachments at the outer edges of the cell. Sarcomatoid cells often overlap one another, again adding difficulty to the diagnosis process. Just as a patient diagnosed with adenocarcinoma may want a second opinion from a mesothelioma specialist, a patient diagnosed with a sarcomatoid carcinoma may also want to seek another opinion from a mesothelioma specialist to ensure proper diagnosis. Prognosis for a patient suffering from a sarcomatoid variety of mesothelioma is often poorer than that of a patient suffering the epithelial variety. As a result, aggressive intervention may be necessary in an attempt to treat sarcomatoid mesotheliomas.
Biphasic mesothelioma, or mixed mesothelioma, simply means that the cellular structure of the mesothelioma cells contain both sarcomatoid and epithelial cells. Biphasic mesotheliomas account for approximately 20-30% of all mesothelioma diagnoses. The epithelial and sarcomatoid cells will often appear in clumps in the tumor sample. The effectiveness of treatment, and life expectancy, of patients suffering from biphasic mesothelioma is poorer than those diagnosed with just epithelial or sarcomatoid mesothelioma.
For more information on asbestos or Mesothelioma, please visit the website of our Mesothelioma Lawyers. If you or a loved one have been exposed to asbestos at work or in the home, and developed any asbestos related disease, you may be eligible to file a claim for damages as a result of the injury. Our nationwide scope and the lawyers we work with have been at the front of this battle for justice for workers and their families for many years, and we will fight for you.

Source: articlesbase
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