Sarcomatoid mesothelioma usually occur the kidneys, but in rare occasions also occurs in the lungs as elongated spindle-shaped cells.
Mesothelioma is a rare form of cancer that is diagnosed in approximately 2,000 to 3,000 people each year in the U.S. This cancer is most often attributed to long-term exposure to asbestos, but may also develop as the result of exposure to radiation, the SV40 virus, or genetic mutations. Mesothelioma affects the protective layer of cells and sac around most organs in the body, the mesothelium. This layer of cement-like cells helps organs to slide easily against each other and other structures in the body when they move, such as when the lungs expand and contract or when the heart beats.
The mesothelium, and likewise mesothelioma, has different names for each region of the body that it is found in. The mesothelium of the lungs is called the pleura; mesothelioma in this region is called pleural mesothelioma. The mesothelium of the abdominal region is referred to as the peritoneum; mesothelioma that occurs here is called peritoneal mesothelioma. Of the heart, the mesothelium is called the pericardium; mesothelioma that occurs here is called pericardial mesothelioma. In the testicular region in males, the mesothelium is called the tunica vaginalis testis; the cancer is called mesothelioma of the tunica vaginalis testis or testicular mesothelioma.
Mesothelioma is subsequently broken into three sub-types: epithelial, sarcomatoid, and biphasic. These sub-types are named for the way that the cells appear under the microscope; tumors are comprised of epithelial, sarcomatoid, or a combination of the two types of cells. Epithelial is the most common form of mesothelioma, affecting 50 to 70 percent of mesothelioma patients. Biphasic mesothelioma is the next most common form of mesothelioma; it affects 20 to 40 percent of all mesothelioma cases. Sarcomatoid mesothelioma affects 10 to 15 percent of all mesothelioma cases.
Sarcomatoid mesothelioma may occur in organs such as the kidneys, but it rarely occurs in the lungs. When sarcomatoid mesothelioma cells appear in the body, they appear as elongated spindle-shaped cells. They have an irregular shape and frequently overlap each other. The nuclei of sarcomatoid mesothelioma are not as visible under the microscope as epithelial mesothelioma cells. The cells may cause difficulty when diagnosing mesothelioma, as they closely resemble cells affected by pulmonary sarcomatoid carcinoma, both in appearance and in characteristics. Diagnosis of this cancer can be difficult using histological methods (meaning an examination of tissue) because of this.
Symptoms and Treatment Options
Early symptoms of mesothelioma may closely resemble those of common ailments, like flu or cold viruses. Symptoms may include fever, fatigue, weakness, weight loss, or abdominal pain or swelling.
Unfortunately, mesothelioma may go undiagnosed in its early stages because it does resemble common symptoms. Sarcomatoid mesothelioma may be diagnosed using imaging methods such as CT scans, PET scans, or MRIs. Diagnostic methods may also include chemical analysis of tissue and cells (immunohistochemistry), or the use of an ultrasound.
Treatment of sarcomatoid mesothelioma, and all types of mesothelioma, typically includes surgical removal of the affected area if possible, followed up with chemotherapy or radiation. Some patients may also opt to use alternative therapies or complimentary therapies, such as acupuncture. Mesothelioma is an aggressive cancer and, regardless of treatments used, is often very difficult to treat. The prognosis for patients with sarcomatoid mesothelioma is an average of seven months.