This type of mesothelioma is the non cancerous form of the mesothelioma and is rare. Recently it was referred to as the "solitary fibrous tumor." It is not a cancer itself but can develop into cancerous forms.
The benign mesothelioma can occur in the pleura or the peritoneum. This usually starts in the sub mesothelium layer that lies beneath the mesothelium of either the pleura or the peritoneum.
This form of mesothelioma also affects the males more than the female population.