Fibrous dysplasia is an uncommon, benign disorder also known as fibrous mesothelioma. The cause of fibrous dysplasia is unknown. They represent 5% of all pleura neoplasms and in 80% of all cases arise from the visceral pleura. The epidemiology of the disease is reported equal between males and females around the age of 50. Fibrous dysplasia is usually asymptomatic, although several disease symptoms have been reported as hypoglycemia, pain and swelling may accompany the lesion, in advanced disease. Chemotherapy has not presented disease control; nevertheless, radiotherapy is efficient and indicated in residual disease. The disease progress is usually benign; however several disease manifestations have been reported. There are several molecular pathways, which are possible activated during the disease progress and therefore the disease expression changes throughout its course.