Biopsy:

If, after performing all above tests, a doctor suspects mesothelioma, a biopsy should be taken to confirm the mesothelioma diagnoses.

If tests and health history are consistent with mesothelioma, a biopsy allows the doctor to make a conclusive diagnosis. The biopsy is an effective diagnostic tool, but is not used first because the removal of sample of cells or tissue is more invasive than a simple X-ray or blood draw.

The most definitive test for diagnosing mesothelioma is a biopsy (tissue sample) of affected or suspicious tissues. In that doctor who specializes in diagnosing and treating cancer removes sample of tissue for microscopic examination by a pathologist. The pathologist usually also looks for the rate of growth and strength of the tumor.

Types of biopsies:

A biopsy may be done in different ways, depending on where the abnormal area is located.

•Fine-needle aspiration biopsy: The physician uses a thin needle to remove a sample of possibly-diseased cells.

•Thoracotomy: In this an incision or small cut is made by physician between two ribs to check inside for signs of disease and to collect a tissue sample.

•Thoracoscopy: If the cancer is in the chest, the doctor may perform a thoracoscopy. In this procedure the incision is made by physician between two ribs and inserts a thin, lighted tube into the chest called a thoroscope. The tube contains a tool to collect cells for examination under a microscope. This test is usually done in a hospital using a local anesthetic or painkiller. If fluid has found in the chest, doctor may drain the fluid out of the body by putting a needle into the chest and using gentle suction to remove the fluid. This is called thoracentesis.

•Peritoneoscopy and laparotomy: If the cancer is found in the abdomen, the doctor may perform peritoneoscopy and laproscopy. These procedures are similar to the thoracoscopy, but the incision is made in the abdominal wall. A thin, lighted tube is used to examine inside the abdomen is called a peritoneoscope. The peritoneoscope is put into an opening made in the abdomen and to collect cells for examination under a microscope. Before the test is done, a local anesthetic will be given. If fluid has collected in your abdomen, your doctor may drain the fluid out of your body by putting a needle into your abdomen and using gentle suction to remove the fluid. This process is called paracentesis.

After the sample has been removed, it will be sent to a pathologist, a physician who specializes in cancer and its diagnosis. This doctor will examine the cells under a microscope to check for any abnormalities that might indicate cancer. In some cases, the first biopsy will remove fluid from around the lungs or from the abdomen. The pathologist will examine the cells found in this fluid for signs of cancer; however, many physicians consider this test insufficient for mesothelioma diagnosis.

Continued from Diagnosis of Mesothelioma: Part – 1

The physical exam should involve a number of imaging tests to search for suspicious cell formation. These typically diagnostic tests include medical imaging scans such as:

Blood tests:

Blood tests are not specifically for mesothelioma. Blood tests will be performed to check white blood cells (WBC) count and platelet count. White blood cells fight infection and platelets are blood cells that help the blood clot.

A new and promising method to detect mesothelioma is MESOMARK assay. This is a blood test used to detect peptides released into the blood stream by mesothelioma cells. Mesothelioma patients usually have an elevated MRP in their blood stream years before actual diagnosis is made. This test is only FDA approved for humanitarian use. It only used to follow someone already diagnosed with mesothelioma (of an epitheloid type) to give an indication of whether or not the cancer is growing.

Some specific substances present in the blood which act as biomarkers, by using one or more biomarkers, a blood test can detect mesothelioma.

Osteopontin, a protein in the liquid part of the blood, is also being investigated as a biomarker for asbestos. In October 2005, The New England Journal of Medicine reported a study showing that persons who have been exposed to asbestos and have pleural mesothelioma, in those patients level of osteopontin is different than in those who have been exposed to asbestos but who do not have cancer.

Mesothelioma is not always diagnosed because the cancer is still unrecognizable. A mesothelioma diagnosis may often be classified as another condition because the symptoms are similar to those of other illnesses. Mesothelioma’s symptoms are not unique and the disease’s relative rarity, cases of mesothelioma misdiagnosed are not uncommon.

Medical history:

Diagnosis begins with a review of the patient’s medical history. The first step involved in diagnosis is providing a full and accurate medical history to your doctor, including details about current and past health concerns, as well as the types of symptoms and signs signs including shortness of breath, chest pains, swollen abdomen, and more you are currently experiencing.

It is important to mention any possible exposure to asbestos. Without revealing this fact, your doctor may not consider asbestos-related diseases in his or her examination. Mesothelioma patients are typically diagnosed within three to six months of their first visit to a doctor with complaints about breathing problems or chest and abdominal pain.

One of the most common carcinogen asbestos develops mesothelioma. Asbestos acts as a carcinogen in the growth of both pleural and peritoneal mesothelioma which occurs in subsiquent stages of triggering and growth. Asbestos fibres are thought to exert their carcinogenic effects via direct physical interactions with the cells of the mesothelium in conjunction with indirect effects following interaction with inflammatory cells such as macrophages.

Asbestos has also been shown to aid the entry of foreign DNA into healthy cells. This foreign DNA can insert itself into the human genome, causing mutations by one of the following mechanisms:

• Activation of oncogenes
• Activation of proto-oncogenes due to incorporation of foreign DNA containing a promoter region
• Prevention of apoptosis
• Inactivation of tumor suppressor genes
• Activation of DNA repair enzymes

Different types of asbestos fibers were studied in rats and mice, showed that long, thin fibres caused a higher incidence of mesothelioma than did short fibres and that cells will actually phagocytose longer fibres more effectively than shorter fibres. Interactive analysis between asbestos fibres and DNA has shown that phagocytosed fibres are able to make contact with chromosomes, often adhering to the chromatin fibres or gets entangled within the chromosome. This direct contact between the asbestos fibre and the chromosomes or structural proteins of the spindle apparatus can induce complex abnormalities. The most common abnormality is monosomy of chromosome 22. Other frequent abnormalities include structural rearrangement of 1p, 3p, 9p and 6q chromosome arms. Common gene abnormalities in pleural and peritoneal mesothelioma cell lines include deletion of the tumor suppressor genes.

Following asbestos phagocytosis, macrophages generate increased amounts of hydroxyl radicals. However, these free radicals are also known clastogenic and membrane-active agents thought to promote asbestos carcinogenicity. These oxidants can participate in the oncogenic process by directly and indirectly interacting with DNA, modifying membrane-associated cellular events, including oncogene activation and perturbation of cellular antioxidant defences. Asbestos also may possess immunosuppressive properties.

The mesothelium consists of an individual band of bedfast to cuboidal beef basic the epithelial lining of the aqueous cavities of the physique including the peritoneal, pericardial and pleural cavities. Asbestos fibers after inhalation deposited in the parenchyma of lung, results in these fibres penetrating through into the pleural membranes where the fibre can then be carried to the pleural surface, thus leading to the development of malignant mesothelial plaques. Fibres from the lungs being transported to the abdomen and associated organs via the lymphatic system. Peritoneal mesothelioma is developed by this process, it remains unresolved. Additionally, asbestos fibres may be deposited in the gut after ingestion of sputum contaminated with asbestos fibres.

It has been known that when there is contamination of pleural membranes with asbestos or other mineral fibres causes cancer (carcinogenesis). Pleural mesothelioma usually begins as discrete plaques and nodules that coalesce to produce a sheet-like neoplasm. At the lower part of the chest tumor growth usually begins. The tumor may invade the diaphragm and encase the surface of the lung and interlobar fissures. The tumor may also grow along drainage and thoracotomy tracts. As the disease progresses, it often extends into the pulmonary parenchyma, chest wall, and mediastinum. Pleural mesothelioma may extend into the esophagus, ribs, vertebra, brachial plexus, and superior vena cava.

Long thin asbestos fibers (blue asbestos, amphibole fibers) are more potent carcinogens than “feathery fibers” (chrysotile or white asbestos fibers). However, the development of mesothelioma in rats has been demonstrated following intra-pleural inoculation of phosphorylated chrysotile fibres. It has been suggested that in humans, transport of fibres to the pleura is critical to the pathogenesis of mesothelioma.

Testicular mesothelioma is extremely rare, very little is known about how it develops. Asbestos fibers once they enter the body get lodged in the spaces of the mesothelial cells causing infection leading to inflammation which further develops into mesothelioma. The fibers cause the cancerous cells to grow abnormally by dividing without restraint. After toxic asbestos fibers have become lodged between the mesothelial cells of the tunica vaginalis.

Asbestos fibers are very difficult for the body to expel and can cause some surrounding cells to mutate into cancerous cells overtime. These cancerous cells then grow and divide far more rapidly than healthy cells, leading to a thickening of the membranes and the development of tumors. The cancer growth may begin on either sub-membrane but is likely to quickly spread to the other. Additionally, tumors on the testicles may be the primary cancer in the patient – or they may be secondary to peritoneal tumors.