Pericardial Mesothelioma –Mesothelioma Symptoms – Mesothelioma Cancer
Mesothelioma: A Cancer That Can Hide In Your Body For Up To 50 Years
Saturday, 13 March 2010 00:40TobiRaikkonen
Mesothelioma is a type of cancer caused by exposure to the carcinogen asbestos. Asbestos was widely used a few decades ago in construction when its ill effects weren't known yet.
Most patients diagnosed withmesothelioma are well into old age due to the fact that once contact with asbestos has occurred, the symptoms start to show anywhere between 15 to 50 years later. Because of this, it is almost impossible to catch the disease in its early stages. To properly identify the disease, x-rays of the chest and pulmonary function tests are required.
3 types ofmesothelioma cancers
There are three known forms ofmesothelioma: Pleural, Peritoneal, andPericardialmesothelioma. The most common is Pleuralmesothelioma which occurs in more than half the cases, second is Peritoneal andlastlyPericardial which is very rare (only about 5 percent ofmeshothelioma cases). Each has its own unique set of symptoms:
- Pleuralmesothelioma: Coughing of blood, chest palpitations, tiredness and difficulty breathing.
- Peritonealmesothelioma: Tiredness, rapid weight loss, vomiting, diarrhea, tummy aches and anemia.
- Pericardialmesothelioma: Chest and heart palpitations, shortness of breath and tiredness.
Mesothelioma in the media
Mesothelioma cases are usually heavily publicized andmesothelioma lawyers take them very seriously due to the huge payouts from settlements by defending companies.
Additionally,mesothelioma can affect anyone. Since the disease is transferred by contact with harmful asbestos chemicals, no one is safe, no matter how fit or strong their immune system may be. Such is the case of all-star athleteMerlin Olsen, a Hall of Fame defensive tackle with the Los Angeles Rams who died yesterday frommesothelioma caused by exposure to asbestos. No one knows how long Merlin Olsen was fighting the disease, as thelife expectancy ofmesothelioma patients vary greatly from individual to individual.
Pericardial Mesothelioma – Mesothelioma Research
Malignant Mesothelioma and Simian Virus 40 (SV40)
Category: Posted on: April 26, 2010 5:00 PM, by Tara C. Smith
Student guest post by Andrew Behan
Malignant Mesothelioma (MM) is a rare type of cancer which manifests itself in the thin cells lining the human body's internal organs. There are three types of MM; pleural mesothelioma, peritoneal mesothelioma, andpericardial mesothelioma, affecting the lining of the lungs, abdominal cavity, and lining of the heart, respectively (1). Pleural mesothelioma is most common, consisting of about70% of all MM cases and has a poor prognosis; patients live a median time of 18 months after diagnosis. (Note: for the purposes of this article, MM will be used to represent pleural mesothelioma exclusively.) Despite its discovery in the mid-1800's, MM was not linked to asbestos until the late 1900's, when case reports of fast-growing lung cancers, different from previously described lung cancers, motivated investigators to uncover undisputed evidence linking asbestos to MM. Measures to reduce/eliminate asbestos from buildings reduced exposure to the cancer-causing agents found within the material, and public health officials remained confident by the year 2000 MM cases would decline in the U.S. and parts of Europe. Despite these predictions, MM cases have not declined. In fact, the incidence of MM is on the rise (1). Consequently, investigators have focused their attention on other factors to explain the steady incidence of MM in theU.S., eventually naming Simian Virus 40 (SV40) as a potential cause of MM.
You might be asking, "SV40? What's that?" SV40 is a virus originally discovered in 1960 in kidney cells of rhesus monkeys. SV40 is dormant and asymptomatic in rhesus monkeys, but was later found to cause kidney disease, sarcoma, and other cancers in animal models. Later on, it was found SV40 attacks p53 gene (a tumor suppressor) and can interrupt the cell's ability to perform apoptosis, or cell death. This makes the cells immortal, leading to tumor formation, or cancer (2). Controversy arose when the discovery of SV40 was found in the rhesus monkey kidney cells because these same cells were being utilized to form the polio vaccine. Consequently, many polio vaccines were contaminated with SV40 and when the vaccine was used to inoculate humans, SV40 was passed to humans along with the inactive form of the polio virus. It was estimated over 98 million Americans received the vaccine from 1955-1963, when a proportion of the vaccine was contaminated with SV40. Of the 98 million vaccinated during this time period, it was estimated 10-30 million of those individuals were exposed to SV40. Naturally, people who received contaminated forms of the vaccine were afraid they would develop cancer from exposure to SV40.
Since the controversy began in 1960, research has been devoted to confirming its role in cancer development in humans, as well as many animal models. As I mentioned above, presence of SV40 in animals has led to tumors and other cancers, and a few studies have found presence of SV40 in humans who have developed MM. For example, Carbone et al. found SV40 in mesothelial cells of humans who had developed MM, but not in the surrounding tissue (3). They did not find SV40 in patients who had other lung cancers, possibly reinforcing the specificity of their findings (3). Overall, 54% of MM cases were found to have SV40 infection within the mesothelial cells (3). The investigators determined more research needed to be done to see if SV40 infection alone could cause MM, or if other factors, such as immunosuppression or exposure to asbestos, were necessary for development of MM.
Other studies were not as convincing. For example, Lopez-Rios et al. reported that initially they detected SV40 in about 60% of MM specimens, and then they determined that most of the positive results were caused by plasmid PCR contamination, and that only 6% of the initially positive samples were confirmed to contain SV40 DNA (4). However, studies have shown the presence of SV40 in human specimens by using several other techniques besides PCR, including Southern blotting, immunostaining, RNA in situ hybridization, microdissection, and electron microscopy" (5).
Thus, the question remains: does SV40 cause MM, or does SV40 infection, in conjunction with asbestos exposure, generate a greater risk for the development of MM? This is a tough question to answer, because although asbestos is no longer mined in theU.S., it is still being imported; workers are still continually being exposed to asbestos. However, the use of asbestos has nearly ceased, decreasing from 813,000 metric tons in 1973, to 1700 metric tons in 2007 (6). The other problem in teasing out SV40 as a cause of MM from asbestos lies in the latency period between asbestos exposure and MM clinical diagnosis. According to the CDC, the latency period for someone who is first exposed to asbestos and clinical disease is 20-40 years. It may be, given asbestos still remains in many buildings, and exposure to it is inevitable when removal is completed, in addition to the long latency period between exposure and disease, that we have not yet come to the dramatic decrease in MM health officials have predicted. Or, is SV40 infection the culprit and the increase in incidence of MM will continue to rise? According to the SV40 Foundation, "SV40 is a problem that federal government authorities have not addressed responsibly because the government's own vaccine programs are responsible for the spread of the virus throughout the western world".(2) It is no question the public has not forgotten, even after almost 50 years, and much more research into this area is needed, to attempt to confirm SV40's causal role, if any, in the development of MM.
(1) Mesothelioma. Retrieved April 2010.
(2) "Treating SV40 Cancers." Retrieved April 2010.
(3) Carbone, M. "Simian virus 40 and human tumors: It is time to study mechanisms." Retrieved from PubMed April 2010.
(4) López-Ríos F, Illei PB, Rusch V, et al. "Evidence against a role for SV40 infection in human mesotheliomas and high risk of false-positive PCR results owing to presence of SV40 sequences in common laboratory plasmids". Lancet. 2004;364:1157-1166.
(5) Yang, Haining et al. "Mesothelioma Epidemiology, Carcinogenesis, and Pathogenesis." http://www.ncbi.nlm.nih.gov.proxy.lib.uiowa.edu/pmc/articles/PMC2717086/. Retrieved from PubMed April 2010
(6) CDC. "Mesothelioma" Retrieved from PubMed April 2010.
Pericardial mesothelioma is much less common than malignant mesothelioma of the pleura or peritoneum. In fact there are only about 150 cases ever reported in the medical literature. It affects the section of the mesothelium called the pericardium (the mesothelial lining of the heart). People in the fourth to seventh decades of life are most likely to have this cancer, and there is a 2:1 male to female ratio. Currently, surgical excision (removal) of the pericardium is the treatment for pericardial mesothelioma, primarily to lessen symptoms of constriction around the heart.
Symptoms of Pericardial Mesothelioma
- Chest pain
- Fluid buildup around the heart
- A mass in the space between the lungs
- Abnormal or difficult breathing (dyspnea)
- Chronic coughing
- Irregular heartbeat (palpitations)
A recent review of the primary pericardial mesothelioma has been published by Vigneswaran and Stefanacci. It is a rare neoplasm with a reported incidence of 0.0022% in an autopsy series of 5,000,000 case studies 212 and a calculated annual incidence of 1 in 40 million in a Canadian epidemiologic survey. An antemortem diagnosis was made in less than one-third of 150 reported cases in the literature. Pericardial mesotheliomas can occur at any age, but people in the fourth to seventh decades of life are most likely to be afflicted, and there is a 2:1 male to female ratio. Patients generally present with a pericardial effusion, congestive heart failure, an anterior mediastinal mass, or tamponade. Diagnosis can be difficult given the nonspecific presentation, and chest radiography may demonstrate only an enlarged cardiac silhouette. Echocardiography can reveal evidence of an effusion, thickening of the pericardium, or mass involvement of the myocardium. CT scanning or MRI can show a thickened pericardium and may help determine invasion into myocardium.
Currently, surgical excision is the treatment for primary pericardial mesothelioma primarily to palliate symptoms of constriction or tamponade.
This 8-centimeter cyst was incidentally found at hysterectomy floating free in the peritoneal cavity, a Zeppelin of the abdomen, if you will. Before making the diagnosis of this benign lesion, it is important for the pathologist to quiz the surgeon concerning the intra-abdominal findings. A cyst excised from a multicystic mesothelioma may look similar to this, and while multicystic mesothelioma may not be a true neoplasm, it has a stubborn tendency to recur locally.
The original photo was taken with a Nikon FE2, Nikkor macro lens, and Ektachrome Elite 100 film. The subject was lit by 4 photofloods. The film is balanced for daylight, so a blue compensation filter was used. The transparency was scanned with a Polaroid SprintScan 35 and edited with Photoshop 3.04. Digital editing included using the Dust and Scratches filter to remove lint from the background, and employing the Levels command to balance the dynamic range.
Photograph by Ed Uthman, MD. Public domain. Posted 30 May 99