The type of malignant mesothelioma depends on the cell in which it began. The most common type of malignant mesothelioma is epithelial mesothelioma, which forms in the cells that line organs.
The other types begin in spindle-shaped cells called sarcomatoid cells or are a mixture of both cell types. Epithelial mesothelioma may grow more slowly and have a better prognosis than other types.
