Reproductive Mesothelioma - A type of mesothelioma

Mesothelioma Of The Tunica Vaginalis

Pleural mesothelioma and peritoneal mesothelioma account for the vast majority of all diagnoses of mesothelioma– the former affects the lining of the lungs, and the latter the lining of the abdomen.  However, pericardial mesothelioma and mesothelioma of the tunica vaginalis do occur.  Each type of mesothelioma is primarily caused by asbestos exposure and inhaling the fibers into the lungs. Currently, there are no known cures for the diseases.

The majority of analyses on these diseases have been carried out on individual case studies. Because of this, developing effective treatment plans for these rare cancers has been a serious problem.  The medical literature only describes a few hundred cases of primary pericardial mesothelioma and even fewer cases for mesothelioma of the tunica vaginalis.

Function of the Tunica Vaginalis

The tunica vaginalis is the mesothelial tissue that encases the testis. It is an outgrowth from the peritoneum and is formed during fetal development. It is made up of a visceral layer (visceral lamina)and a parietal layer (parietal lamina). The visceral layer covers the greater part of the testis and theepididymis, while the parietal layer covers a larger area, reaching upward and below the testis, including it and some surrounding tissue as well. Mesothelioma of the tunica vaginalis is the rarest of mesothelioma malignancies, with fewer than one hundred individual cases in the literature.

Mesothelioma of the Tunica Vaginalis

As in other forms of mesothelioma, incidence has mainly targeted men over the age of 50. It typically presents as a testicular mass and is often pre-operatively misdiagnosed as testicular cancer. Surgeryhas been the preferred treatment modality, although many doctors expect Alimta and cisplatin to have beneficial effects as well. While metastatic behavior has been reported, localized malignancy seems to be the norm with this rare cancer.  Individual prognosis reports seem to be quite varied: in some cases, the tumor presented with aggressive behavior, while other patients experienced long-term remission. In general, median survival averages twenty-three months. Age at time of diagnosis greatly affects prognosis: the literature notes that men under 60 have shown significantly better survival rates than man over 60 have.

Pericardial Mesothelioma - A type of mesothelioma

Pericardial Mesothelioma

Pleural mesothelioma and peritoneal mesothelioma account for the vast majority of all diagnoses of mesothelioma. However, pericardial mesothelioma and mesothelioma of the tunica vaginalis do occur. The majority of analyses on these diseases have been carried out on individual case studies. Because of this, developing effective treatment plans for these rare cancers has been a serious problem.

The medical literature only describes a few hundred cases of primary pericardial mesothelioma and even fewer cases for mesothelioma of the tunica vaginalis.

Function of the Pericardium

The pericardium is a tissue sac that contains the heart and the primary blood vessels. It has two layers: the fibrous pericardium and the serous pericardium. The fibrous pericardium is the outermost layer and is made up of connective tissue that protects the heart and anchors it to the surrounding walls. It’s a dense, thick tissue layer. The inner layer, the serous pericardium, is itself made up of two layers: the parietal pericardium, which is directly connected to the fibrous pericardium, and thevisceral pericardium which forms the outer surface of the heart. In between the parietal and visceral pericardium is the pericardial cavity, where pericardial fluid is secreted to ease the movement of the heart within its space. Like the pleura and the pleural cavity, if the function of the pericardium becomes compromised, the pericardial cavity can develop a build-up of the cavity’s lubricating fluid and this can impact the heart’s proper function. This build-up is known as a pericardial effusion. When one of the layers of the pericardium becomes malignant, it is known as pericardial mesothelioma.

Overview of Pericardial Mesothelioma

The literature on pericardial mesothelioma suggests a highly aggressive cancer with an average life span of less than six months from diagnosis. With so few cases to actively study, the information regarding treatments, symptoms and prognosis is limited. In fact, many patients are unaware they have pericardial mesothelioma and the diagnosis is made only during autopsy. For patients diagnosed when still living, commonly reported symptoms include fever, dyspnea, night sweats and many present with symptoms of congestive heart failure and pericardial effusions. Surgery has been used for palliative benefit for some, but the literature suggests the disease is not very amenable to treatment.

Recent Case Study of Pericardial Mesothelioma

A case of primary pericardial mesothelioma in a forty-four year-old man has recently been covered in a medical journal. This man was treated with Alimta plus carboplatin, which is the FDA-approved standard of care for mesothelioma. He responded well to the treatment and lived for sixteen months after his initial diagnosis, exceeding the anecdotal average by nearly 10 months. The researchers suggest that using standard mesothelioma treatments for the rarer forms of the disease may still have beneficial effects for the patient.

Peritoneal Mesothelioma - A type of Mesothelioma

Peritoneal Mesothelioma

Peritoneal mesothelioma is a cancer of the peritoneum, which is the lining of the abdomen. It is the second most common type of mesothelioma and with pleural mesothelioma makes up the vast majority of all mesothelioma diagnoses. Incidence rates for peritoneal mesothelioma vary, but it’s thought to occur in ten to twenty percent of malignant mesothelioma diagnoses. There is some evidence to suggest that diagnoses of peritoneal mesothelioma in the United States are on the rise.

While all forms of mesothelioma affect men more than women, if a woman is diagnosed with mesothelioma, it is more likely to be peritoneal mesothelioma than it is pleural mesothelioma. Neither of these types of mesothelioma have effective cures, and the prognosis is often grim: the average survival time varies from 4 – 18 months after diagnosis.

Function of the Peritoneum

The peritoneum is a serous membrane that lines the body’s abdominal cavity and secretes a fluid to provide for increased movement and reduced friction among the organs in the midsection. Like the pleura, there are two parts to the peritoneum: the visceral peritoneum and the parietal peritoneum. The visceral peritoneum covers the internal organs and makes up most of the outer layer of the intestinal tract. The parietal peritoneum lines the abdominal cavity.

Development of Peritoneal Mesothelioma

As with all forms of mesothelioma, peritoneal mesothelioma has been conclusively shown to be caused only by exposure to asbestos. The carcinogenic process, i.e., the manner in which tissue becomes cancerous, is still not fully understood, but it begins with an initial exposure to asbestos. Asbestos fibers are very durable and cannot be fully eliminated by the body’s immune system. Over time, they cause chronic inflammation and the development of a fibrosis that leaves the affected tissue with calcifications and plagues that impede the peritoneum’s proper functioning. In some cases, these antigenic fibers lead to the development of mesothelioma.

Unlike pleural mesothelioma, where it’s clear that fibers were breathed-in and then settled in the pleural cavity and lungs, it is still not understood by scientists just how asbestos fibers become lodged in the peritoneum. There are three theories:

• Asbestos fibers that have been broken down into smaller pieces in the lungs are carried through the blood stream to the abdomen lining.
• Asbestos fibers were ingested with food or drink. Clouds of asbestos dust were common in factories and ships. Some fibers could have settled on workers’ food.
• Inhaled asbestos fibers are transported through the lymphatic system to the peritoneal cavity.

As the incidence of peritoneal mesothelioma increases, more research is being devoted to its study and scientists are hopeful that more advances in our understanding of the disease are right around the corner.

Symptoms and Diagnosis of Peritoneal Mesothelioma

One of the most common symptoms of peritoneal mesothelioma is abdominal pain, due to tumor invasion of the peritoneum which often comprises both its elasticity and its ability to filter fluids throughout the abdominal cavity. However, like the symptoms of pleural mesothelioma, it is often difficult to diagnose peritoneal mesothelioma in its early stages because its symptoms often mimic the symptoms of other abdominal illnesses.

Some of the symptoms shared by peritoneal mesothelioma and other illnesses include:

• Upper abdominal pain
• Abdominal swelling due to fluid retention or tumor growth
• Cough and shortness of breath
• Fever
• Weight loss
• Fatigue
• Anemia
• Digestive disturbances

Because of these similarities and the relative rarity of mesothelioma in the general population, the disease often grows untreated because the doctor was treating a different ailment. More invasivediagnostic techniques are not often used until the symptoms become more pronounced. Thus, when one is actually diagnosed with peritoneal mesothelioma, one’s cancer is often quite advanced. This could mean that multiple tumors have already invaded the peritoneum, that the cancer has spread to the lymph nodes and/or that the cancer has metastasized to other parts of the body, such as the lungs or the heart.

Treatment and Prognosis of Peritoneal Mesothelioma

As we stated in the introduction to pleural mesothelioma, all general prognostic guidelines and treatment regimens for mesothelioma are based on the pleural form of the disease. Because of this, most of the information we have regarding treatment and prognosis of peritoneal mesothelioma is anecdotal. However, this does not mean that the data should be ignored. Scientists have been gathering more and more information about peritoneal disease and clinical studies are ongoing that specifically study treatment regimens for this variety of mesothelioma.

Like all forms of mesotheliomas, there is no cure for peritoneal mesothelioma. However, peritoneal mesothelioma often presents with a better prognosis and a longer life expectancy than does pleural mesothelioma. Histologically, peritoneal mesothelioma is most often of the epithelial subtype, which is the type most amenable to treatment. The sarcomatous subtype rarely presents in peritoneal mesothelioma, so many treatment regimens seem to have a better response rate with peritoneal mesothelioma. While the pleural disease has an average life expectancy of a year to 16 months from diagnoses, it is not uncommon for victims of peritoneal disease to live two to five years after diagnosis.

A notable example of greater-than-average life expectancy, as well as one of the most famous people diagnosed with mesothelioma, was Harvard University professor Stephen J. Gould, an internationally renowned paleontologist and evolutionary biologist. Dr. Gould was diagnosed with peritoneal mesothelioma in 1982. After an initial period of depression, he became hopeful and was determined to not let the statistics regarding life expectancy beat him. When he finally died in 2002, it was from another form of cancer, totally unrelated to his mesothelioma. Dr. Gould has written about his experience with peritoneal mesothelioma and his determination to not let simple statistics dictate his reaction to his diagnosis in the essay, “The Median Isn’t the Message.” We recommend Dr. Gould’s essay for everyone who has been diagnosed with this disease.

Dr. Gould’s experience certainly may not be standard, but his hopeful approach to his diagnosis cannot be discounted. Peritoneal mesothelioma is a very serious disease and it must be taken seriously as such. However, treatments are improving, as are the prognoses of those diagnosed.

Pleaural Mesthelioma - A type of Mesothelioma

Pleural Mesothelioma

Pleural mesothelioma is a form cancer that is almost always caused by asbestos exposure and is most commonly found in the outer lining of the lungs called the mesothelium. Pleural mesothelioma is the most common type of mesothelioma and has been studied to a far greater degree than any of the other forms of the disease. The vast majority of treatment options and all of the staging guidelinescurrently utilized in the diagnosis of mesothelioma are based on pleural mesothelioma. Because of this, when most people speak of “mesothelioma,” they are usually speaking of malignant pleural mesothelioma. After pleural mesothelioma, peritoneal mesothelioma accounts for the majority of other diagnoses.  Although ongoing research is being conducted to find a cure, or cures, for mesothelioma, all types are still considered to be incurable in the medical community.  

Function of the Pleura

Pleural mesothelioma occurs when one of the pleura in the chest cavity becomes malignant. The pleurae are serous membranes, which mean they secrete a lubricating fluid, called serous fluid. There are two pleurae in the chest cavity and their job is to protect and cushion the lungs by secreting fluid that allows the lungs to move smoothly within the chest cavity when breathing. While they certainly serve an important purpose, each pleura can be removed if it becomes damaged or diseased. The ease of which it can be removed is dependent on which of the pleural surfaces becomes malignant: the parietal pleura or the visceral pleura.

The parietal pleura lines the inside of the chest and covers the ribs and the pericardium. It is a fairly thin tissue between two and three millimeters thick and is the more easily removed of the two pleural surfaces. At a single millimeter in thickness, the visceral pleura is barely half the width of the parietal pleura. It directly covers the lung itself, which makes extraction of the visceral pleura without subsequent damage to the lung very difficult.

Development of Pleural Mesothelioma

While science has conclusively shown that mesothelioma is caused only by asbestos exposure, the actual biological processes by which it develops are still being investigated. In essence though, pleural mesothelioma develops when jagged asbestos fibers are inhaled and settle in and around the lungs. The fibers become lodged in its small passageways and in the surface of its lining. The body’s immune system is able to process and breakdown some of these asbestos fibers, but invariably many still remain. Over time, the fibers cause chronic inflammation, the development of pleural fibroses (a thickening of the pleural surfaces) and pleural effusions (buildup of fluid in the pleural spaces) and in many people, cancerous cell development. If the fibers create a malignancy in the lung itself, one is diagnosed with lung cancer. If the malignancy begins in one of the pleural tissues, one is diagnosed with pleural mesothelioma.

It is because of the proximity of the pleurae to the lung that many people mistakenly think of pleural mesothelioma as a form of lung cancer. While a pleural malignancy can invade the lung, the tumor’s origin site is still the pleura, so pleural mesothelioma should never be treated as lung cancer.