No, Papillary Mesothelioma is the only type of Mesothelioma that can have either a benign or malignant presentation. If you are diagnosed with Well-Differentiated Papillary Mesothelioma, it is crucial to ask your doctor if you have a benign or cancerous form. There is ongoing research to determine if the benign condition is just an earlier Mesothelioma cancer stage.