Are there different types of mesothelioma?

Are there different types of mesothelioma? 

Looking under the microscope, the pathologist is able to distinguish three distinct types of mesothelioma based on the appearance of the cells. The majority of mesothelioma is of the epithelial type, which, under the microscope, resembles adenocarcinoma cells (like those found in lung cancer). 

Special staining will be applied to your biopsy specimen to differentiate epithelial mesothelioma from lung cancer and from other tumors that are adenocarcinoma. Sarcomatoid mesothelioma is a more aggressive type of mesothelioma. Sarcomatoid occurs in approximately 7-20% of all malignant mesotheliomas. Biphasic or mixed, mesothelioma accounts for approximately 20-30% of malignant mesothelioma diagnoses, and is a combination of both epithelial and sarcomatoid mesothelioma.

As the field of mesothelioma science evolves, it is important to know the type of mesothelioma as we are developing agents that target mesothelin, a protein found on the outside of epithelial mesothelioma cells. This may prove to be a very important way of treating malignant mesothelioma by using "smart drugs" with known targets rather than a more generalized approach to treatment.

Surgical series are also reporting statistical differences among the various subtypes of mesothelioma. There are currently plans underway to develop strategies to determine who benefits from each type of treatment modality. In the future, we hope to guide the therapy for mesothelioma based on patients' unique cancer signature of proteins, genes, or other molecules.