Solitary fibrous tumor of the central nervous system: report of an additional 5 cases with comprehensive literature review

Solitary fibrous tumor (SFT) of the central nervous system was first described in 1996. A number of cases have been reported since. The authors present 5 new cases: 4 intracranial and 1 intraspinal. All patients were adults (age range, 47 to 75 years); 4 were male and 1 female; 4 cases were primary tumors; and 1 was a second tumor recurrence. All patients were surgically treated with gross total removal. All cases were histologically examined with immunohistochemical confirmation; 2 tumors exhibited diffuse classic histology, 1 tumor was a cellular variant, 1 tumor was myxoid, and 1 was predominantly classic with focal myxoid features and focally pleomorphic. The postoperative course was uneventful in all. The patient with the cellular variant experienced 2 local recurrences and eventually died of disease 10 years after the initial diagnosis. The patient with the myxoid variant—the tumor studied—which was the second recurrence of a previously misdiagnosed fibrous meningioma surgically treated 15 years earlier, had a recurrence after 2 years for the third time and eventually died of disease. Three patients are alive and well 11.6, 6, and 4 years after surgery. SFT is a rare tumor that needs to be differentiated from some mimickers, mainly fibrous meningioma, hemangiopericytoma, and with regard to the myxoid variant, also adult-onset myxochordoid meningioma and myxoid peripheral nerve sheath tumor. Immunohistochemistry is crucial for the correct diagnosis of SFT. The authors also performed a review of the literature and found a little more than 200 cases on record.