Localized:
a. Benign – with appropriate surgical resection (1 cm surgical margins), most patients have no further complications of the disease. Transformation from a benign to a malignant mesothelioma is a possibility without proper surgical resection.
b. Malignant – these rates very greatly across literature. Generally speaking, without treatment the disease will be fatal in 4-8 months. With multi-modality treatment (surgery, radiation therapy, and chemotherapy), most patients survive from 8-14 months with some surviving up to two years.

Diffuse:
Diffuse mesothelioma has the poorest prognosis, with an overall average life span after diagnosis of 1 year – with or without treatment. In general, the extent of tumor invasion (chest wall, mediastinum, and diaphragm being common) correlates with length of survival.