Sarcomatoid Mesothelioma: A Deadly Curse Of Asbestos
Sarcomatoid Mesothelioma is a quite uncommon type of cancer caused due to asbestos exposure. While it is difficult to diagnose Sarcomatoid Mesothelioma, it hardly responds to any type of therapy. This is the most serious of all asbestos-related diseases. The possibility of finding this type of cancer is on the lips and the larynx. However, in certain cases it may affect the oral cavity as well. Like all other forms of mesothelioma cancers, this cancer is a fatal disease and hardly responds to any method of treatment. Even though radiation therapy is recommended for the treatment of these cancerous tumors, but some of them may not be radiosensitive and may defy radiation for treatment.
The differentiation of sarcomatoid mesothelioma from other cell tumors by light microscopy is quite difficult. The role of immunohistochemistry is also not well defined in its diagnosis. Since sarcomatoid mesothelioma is not always cytokeratin-negative, the distinction between it and sarcoma is not always possible. In this context, the doctors undertook a study to investigate the utility of diagnostic immunohistochemistry for distinguishing sarcomatoid mesothelioma from its histological mimics, high-grade sarcoma and pulmonary sarcomatoid carcinoma.
For its study, the researchers stained the mesotheliomas with sarcomatoid components. They assessed the intensity and distribution of staining with the help of a semi quantitative scale. Only tumors with unequivocal staining were considered positive for tabulation. Then they compared the immunophenotypic profiles of these tumors with 24 high-grade sarcomas. The sarcomatoid carcinomas were also stained for thyroid transcription factor-1 (TTF-1).
The study showed that Cytokeratin 5/6 stained most of the epithelioids but the sarcomatoids were rarely stained. On the other hand, Calretinin and thrombomodulin each stained 70% of sarcomatoid. All 10 sarcomatoids were negative for TTF-1. This led to the conclusion that a wide immunophenotypic overlap exists among different sarcomatoids. Cytokeratin and calretinin have the most value in differentiating different sarcomatoids. Clinicopathological data, especially information about the gross appearance of the tumor is quite important for sarcomatoid tumors. Thus, it should be noted and carefully correlated with microscopic and immunohistochemically findings.
What Is Mesothelioma Sarcoma?
Between the two forms of tumors of the mesothelioma, which are either benign (non-cancerous) or malignant (cancerous), the latter is more common and dangerous, popularly known as mesothelioma. Mesothelioma is characterized by its dangerous potential to spread to other parts of the body.
There are three different types of Mesothelioma:
1) Ephitheliod: It affects the membranous tissue covering the internal organs and surfaces of the body. Though majority of the mesothelioma cases occurring today belong to this type, it has the best prognosis (outlook for survival or treatment).
2) Sarcomatoid: It is also known as mesothelioma sarcoma. It arises from supportive tissues such as bones, muscles, cartilages and fats. About 7% to 20% of mesothelioma cases are of this type.
3) Mixed/Biphasic: 20% to 35% of mesothelioma cases belong to this type. It carries both the features of the above two types.
The treatment options remain the same for all the types.
Physical Aspects of Sarcomatoid Mesothelioma
Mesothelioma arising from the chest cavity are known as pleural mesothelioma and amounts to an approximate three fourths of the total cases. Peritoneal mesothelioma, which starts and spreads in the abdomen, constitutes 10% to 20% mesothelioma cases. Mesothelioma affecting the covering of the testicles, which is in fact an out- pouching of peritoneum into the scrotum, is rather uncommon. Cases of Pericardial Mesothelioma that starts in the cavities of the heart are also very rare.
Mesothelioma and the Masses
New cases of mesothelioma, even though they are less common, amount from 2000 to 3000 every year only in the United States. Most of the patients diagnosed with mesothelioma are from the age group of 50 years and above with majority being the people in the seventies.
This is primarily due to their exposure to asbestos in the 1940s and 1950s or even earlier. Exposure victims of later years i.e.1970s and 1980s are yet to be diagnosed. Men are more susceptible than females with male victims constituting 3 to 5 times higher in numbers than females. This is probably because during that period women liberation movements were started, which resulted into barring them from construction works. On the racial parameters, it is more common among the Caucasians than African Americans.
Even though mesothelioma sarcoma cases are rare, they are extremely dangerous. People diagnosed with the disease are mostly in their last and critical stages, making their treatment more difficult in comparison to other forms of cancer. The survival time ranges from one to two years. With unparallel advancements in modern science and medical technology, chances of mesothelioma treatment and recovery have always been increasing.
The good news is that the patients suffering from mesothelioma sarcoma can file lawsuits for seeking compensation against the companies responsible for asbestos exposure.