What Causes Peritoneal Mesothelioma?

What causes peritoneal mesothelioma? The answer is clear cut, it is only caused by exposure to asbestos, a microscopic natural fiber that was used heavily in industry. Asbestos is said to reach the abdominal wall by one of two methods. The first is through ingested asbestos fibers which are processed through digestion and become lodged in the peritoneum. The other method is through the lungs and lymph nodes, by inhaled asbestos fibers.Malignant mesothelioma of the pleura is also known to metastasize directly into the abdominal cavity if its spread is not slowed.

Many of those who have worked with asbestos materials have developed peritoneal mesothelioma as a result of exposure to friable asbestos fibers. Asbestos was used in myriad industrial materials and construction products. Exposure to asbestos was common in aluminum plants, steel mills, power plants, and naval shipyards.

Peritoneal mesothelioma is a relatively rare disease, with only 200-500 diagnoses each year in the United States being documented. Risk however, is sustained in those who have been exposed to asbestos. Even those exposed many years ago are potentially at risk for the development of malignant peritoneal mesothelioma. Latency between exposure to asbestos and the development of peritoneal mesothelioma symptoms can be anywhere from 20-50 years. Misdiagnosis is also common because peritoneal mesothelioma symptoms closely mimic minor stomach/abdominal discomfort and hernia. Nevertheless, those with clear asbestos exposure history should be aware of the disease and speak with their doctor or cancer specialist if they believe they may be experiencing symptoms related to mesothelioma.

Peritoneal Mesothelioma Treatments

Peritoneal mesothelioma treatments can be difficult since by the time the patient is aware of the cancer it has typically progressed to later stages of development, but doctors typically recommend treatment to patients to combat the cancer and aid in pain relief. Common treatments used for patients with mesothelioma include surgery, chemotherapy and radiation . Chemotherapy medications and radiation therapy target and kill cancerous cells that rapidly divide.

While no known cure for peritoneal mesothelioma exists, patients may elect to undergo a combination of treatments or participate in clinical trials to alleviate pain and increase the quality of life. Clinical trials are studies that qualifying patients may participate to test up-and-coming medications and treatments. All potential treatment options and medications must go through clinical trials before they are deemed safe and effective.

Chemotherapy Drugs

Many patients, however, are not good candidates for surgery since mesothelioma has often spread too extensively or because the patient’s general health is too poor to cope with the stress of surgery. These patients may elect to participate in palliative treatment options that do not attempt to cure a patient, but work to relieve symptoms and improve the quality of life for peritoneal mesothelioma patients.Some peritoneal mesothelioma patients may opt for intraperitoneal chemotherapy, where medications are injected directly into the peritoneum immediately following surgery. In some cases, patients may first go through radiation therapy to shrink tumors before undergoing surgery.

Peritoneal Mesothelioma Diagnosis

Symptoms of peritoneal mesothelioma are not necessarily unique to the disease, so diagnosing peritoneal mesothelioma requires more than an observation of symptoms. Most symptoms associated with abdominal mesothelioma accompany other, often less serious, medical conditions. Most peritoneal mesothelioma diagnoses are made when the malignancy is in an advantage stage and diagnosis, alone, takes on average four months.

Diagnosing Peritoneal Mesothelioma

The first step in diagnosing peritoneal mesothelioma is a physical exam and patient history. If your doctor does not ask about your work history and potential mesothelioma risk factors, let him or her know about your asbestos exposure. A history of asbestos exposure is an important clue for your physician or diagnostician and neglecting to mention this could delay diagnosis.

Following a physical exam and a patient’s description of their symptoms, the next step in diagnosing peritoneal mesothelioma is usually to get some type of imaging of the abdomen. An x-ray, CT (or CAT) scan, or MRI may be performed. Although mesothelioma cannot be definitively diagnosed by visual confirmation, tumors may be visible, or an excess of serous fluid may be seen. The three primary types of peritoneal mesothelioma tumor development seen are:

    “Dry-painful”The most common of peritoneal mesothelioma presentations, one large or several small but similarly located peritoneal masses are seen.”Wet”Associated with ascites and swelling, no solid masses but small nodules and plaques are visible in this type of peritoneal mesothelioma.”Mixed”A combination of both “wet” and “dry” types of peritoneal mesothelioma.

In cases where fluid has accumilated in the abdomen, paracentesis may be performed; a needle is inserted into the peritoneal cavity to drain the excess fluid from the abdomen. Usually, cytologic testing on this ascetic (peritoneal) fluid (where specialists examine the fluid for abnormal cells) is not considered effective to diagnose peritoneal mesothelioma.

The next step in effectively diagnosing peritoneal mesothelioma is the collection of a biopsy. A biopsy is required so that the tissues and cells in question can be examined at a microscopic level. A fine-needle aspiration biopsy is usually performed at first because they are minorly invasive and quite safe. Immunohistochemical staining of the biopsy is regularly performed on collected samples. Sometimes referred to casually as “immunos,” these tests use special substances that color proteins and markers that indicate cancerous cells.

Sometimes further testing is required to make a definitive diagnosis, whether because the initial biopsy testing was inconclusive or a fine-needle biopsy could not be taken because of the location of the tumor and/or fluid pockets. If this is the case, the next step performed is often a peritoneoscopy. During this procedure, a local anesthetic is administered and a small incision allows the doctor looks inside the abdomen with a special tool called a peritoneoscope.

During the peritoneoscopy, a larger biopsy sample may be collected for testing. Finally, if more tissue is required for testing, diagnositic surgery or “open” biopsy may be required.

Diagnosing peritoneal mesothelioma is very difficult, and cases of peritoneal mesothelioma misdiagnosed or undiagnosed are unfortunately not uncommon. It is important to share your case history of work experience (especially in shipyards and at construction sites) and asbestos exposure potential with your physicians if you feel mesothelioma is a risk. Asbestos fibres can also be carried into the home on clothing, inadvertently exposing the deadly fibres, and the risk of mesothelioma, to family members.

In addition to determing a diagnosis, many diagnostic test also help determine the stage the cancer is in, providing a better idea of a patient’s prognosis. The chance of recovery depends on the size of the cancer, where the cancer is, how far the cancer has spread, how the cancer cells look under the microscope, how the cancer responds to treatment, and the patient’s age. Peritoneal mesothelioma is usually diagnosed when it has had time to advance; as with most types of cancer, early diagnosis is an excellent first step in fighting the disease.

Peritoneal Mesothelioma

Peritoneal mesothelioma, a cancer of the lining of the abdominal cavity, is less common than the pleural form, comprising approximately one-fifth to one-third of the total number ofmesothelioma cases diagnosed. According to the SEER (Surveillance, Epidemiology, and End Results) database, these diagnoses are approximately 54.7 per cent male versus 45.3 per cent female, with the median age being 65-69. The latency period appears to be shorter forasbestos-exposed individuals with symptoms appearing 20-30 years after exposure rather than the 30-40 year latency more commonly associated with pleural mesothelioma.

Peritoneal Mesothelioma Symptoms

A patient with mesothelioma usually begins showing symptoms 15 to 50 years after their exposure to asbestos. The cancer may take decades to develop in the body and symptoms do not arise until after the cancer is present. Common early symptoms of mesothelioma include fatigue, coughing, shortness of breath and reduced respiratory function. Many patients are unaware they have developed mesothelioma or the severity of their condition as mesothelioma symptoms typically resemble symptoms of less serious illnesses and occur so long after the initial exposure.

What are the Symptoms of Pleural Mesothelioma?

Most pleural mesothelioma symptoms affect the respiratory system. Although they are rarely part of a patient’s initial presentation and are typically discovered by imaging tests, pleural thickening or pleural plaques are also indicative of mesothelioma.

The most commonly reported symptoms of pleural mesothelioma include:
  • Chest pains
  • Shortness of breath (dyspnea)
  • Reduced chest expansion
  • Barely audible or harsh breathing sounds
  • Dry cough or wheezing
  • Pleural effusions

These benign lesions can be as large as 6 cm in diameter and appear in scattered clusters across the visceral and parietal pleural surface. In a 2011 study of 221 pleural mesothelioma patients, symptoms were reported with the following frequency:

  • 90% of patients presented pleural effusions
  • 79% of patients experienced shortness of breath
  •  64% of patients reported chest pain
  •  36% of patients developed a chronic cough
  •  30% of patients experienced weight loss

What are the Symptoms for Other Types of Mesothelioma?

Peritoneal mesothelioma:

Abdominal pain is the first symptom that most peritoneal mesothelioma patients exhibit. This is commonly followed by abdominal enlargement and tenderness. Ascites, fluid buildups between the peritoneum and the abdominal organs, are very common, but they often develop later in the progression of the illness. In a study of 13 peritoneal mesothelioma patients, 77 percent of participants developed ascites.

Peritoneal mesothelioma is also associated with a loss of appetite that often results in weight loss, abdominal distention/pelvic mass and abdominal hernias. In one study, 69 percent of peritoneal mesothelioma patients lost weight. Patients may also note bowel obstruction very late in the progression of peritoneal mesothelioma. Additionally, one Australian study found that 10 percent of all diffuse malignant peritoneal mesothelioma patients experienced short, mild seizures.

  • 69% of patients experienced weight loss or loss of appetite
  • 77% of patients developed ascites
  • Abdominal pain is an early sign of peritoneal mesothelioma
  • Bowel obstruction generally occurs later

Pericardial mesothelioma:

The few available case reports on pericardial mesothelioma name difficulty breathing and chest pain as the symptoms of this subtype. These symptoms are the result of the pericardium thickening.

Testicular mesothelioma:

The only consistent sign that has been presented by patients with testicular mesothelioma is a lump in the testes. Testicular mesothelioma is incredibly rare, yet as more studies are conducted, additional symptoms may be revealed.

What Symptoms Indicate Metastatic Spread?

Not all mesothelioma symptoms are confined to the site where the cancer originates. The symptoms that are most closely related to local invasion include:

Localized spread to the lymph nodes is most common and occurs in approximately 44% percent of cases.

  • Dysphagia (coughing/spitting up blood)
  • Horner’s syndrome (or other neurological syndromes)
  • Laryngeal nerve palsy
  • Nerve involvement of the arm

Paraplegia can occur if the cancer spreads to the spinal canal. Metastatic mesothelioma can also obstruct the superior vena cava. Hypoglycemia has also been reported as a clinical feature of invasive mesothelioma, yet this primarily occurs in patients with rare localized fibrous mesothelioma. Clubbing of the fingers and hypertrophic pulmonary osteoarthropathy (HPOA) are even rarer but occur in a handful of malignant mesothelioma cases, primarily when asbestosis is also present.

When do Mesothelioma Symptoms Emerge?

Typically, mesothelioma patients notice the first signs of their disease 30 to 50 years after they were first exposed to asbestos. This latency period is not significantly different between varying subtypes of mesothelioma, but some studies have noted a shorter latency period for peritoneal mesothelioma (20 to 30 years) than pleural mesothelioma. However, in one 2011 study of 191 malignant mesothelioma cases, women were found to have a longer latency period than men:

A larger retrospective study of 1,690 mesothelioma patients found the median latency period to be 32 years, while an even larger 2006 Italian study of 5,173 mesothelioma patients reported an average latency of 43.6 years. Once signs of mesothelioma finally emerge, they are typically mild. Many patients may not pay attention to them when they first arise, only seeking a medical consultation when symptoms intensify. Additionally, a high percentage of mesothelioma patients have other respiratory diseases and the onset of mesothelioma is often misinterpreted as a progression of an existing condition such as COPD.

Because of the long latency period, symptoms are not always addressed right away. One study found that the interval between the first presentation of symptoms and referral to appropriate treatment was as high as 39 months.

What is Peritoneal Mesothelioma

Malignant peritoneal mesothelioma  is an extremely rare cancer. Only 100 to 500 cases are diagnosed in the US each year, making up less than 30% of all mesothelioma cases.

Peritoneal mesothelioma is a cancer affecting the abdominal lining, or peritoneum (paira-tin-e-um), which is why is is sometimes referred to as abdominal mesothelioma. This membrane supports and covers the organs of the abdomen.

The peritoneum is made of two parts, the visceral and parietal peritoneum. The visceral peritoneum covers the internal organs and makes up most of the outer layer of the intestinal tract. Covering the abdominal cavity is the parietal peritoneum.

Cells in these linings secrete a fluid which allows organs to move against one another. For instance, as the intestines move food through the body. The cells of the mesothelium are designed to create fluid, but the cancer can cause them to overproduce, creating a build up of excess fluid in the abdominal cavity.