Sarcomatoid mesothelioma
accounts for only about 10 to 15% of the mesothelioma cancer cells and it is the least common form of mesothelioma. These cells are typically oval shaped, but more irregular, and with the nucleus not as clearly visible under an electron microscope as the nuclei of the epithelioid mesothelioma cancer cells. Because the oval irregular shape is a common form of a cancer cell type, sarcomatoid mesothelioma can be confused with sarcomatoid carcinoma and with sarcoma.
sarcomatoid mesothelioma Versus Sarcomatoid CarcinomaSarcomatoid mesothelioma is often confused with a wide variety of other types of cancer because of the sarcomatoid appearance, including sarcomatoid carcinoma. Although sarcomatoid cancer appears in other parts of the body, such as the kidney, sarcomatoid cancer is relatively rare in the lungs. Up to 1.3% of lung carcinomas are of the sarcomatoid type.
Pulmonary sarcomatoid carcinoma is the type most often confused with sarcomatoid mesothelioma. Similar to sarcomatoid mesothelioma, lung sarcomatoid carcinomas are much more likely in men (four times more likely than in women) and there is a strong association with smoking. Also, patients can present with similar symptoms, such as chest pain, pleural effusions and respiratory difficulty.
Sarcomatoid Mesothelioma Versus SarcomaSarcomatoid mesothelioma can also be confused with high-grade sarcoma. Sarcoma is a form of cancer that arises in the supportive tissue, such as bone, cartilage, fat or muscle. (This is as opposed to carcinoma, which arises from the epithelium.) If the sarcoma becomes involved with the pleural surface, then it can be difficult to differentiate sarcoma from sarcomatoid mesothelioma.
Appearance of the cells can be similar under an electron microscope and the staining of the tumor cells can provide similar results. In these cases, the pathologist must be careful to compare the appearance and staining of the cells, along with the overall appearance (localized versus diffuse pleural-based mass) and regularity of the tumor when making a definitive diagnosis of malignant mesothelioma.
If you or a loved one has been diagnosed with high grade sarcoma of the lungs or pulmonary sarcomatoid carcinoma and you have had previous asbestos exposure, it may be best to seek a second thorough examination from your current physician or from an oncologist who specializes in mesothelioma.
