Solitary fibrous tumors in the central nervous system. A clinicopathologic review of 18 cases and comparison to meningeal hemangiopericytomas.
BACKGROUND
Solitary fibrous tumors (SFTs) of the central nervous system are rare neoplasms that usually present as dura-based masses and clinically resemble meningiomas. Histologically, they can be similar to fibrous meningioma or hemangiopericytoma (HPC). In particular, densely cellular regions seen in some SFTs can be indistinguishable from HPC. Little is known about the biological behavior of SFTs, although most seem amenable to total resection.


OBJECTIVE
To define the clinicopathologic spectrum of SFTs in the central nervous system and to outline their differences from HPC and meningioma.


METHODS
We present the clinicopathologic features of 18 patients with SFT and compare them with those of an age- and sex-matched cohort of HPCs.


RESULTS
Eleven SFTs were supratentorial, 3 were infratentorial, and 4 were intraspinal. Four of the 18 tumors were intra-axial (2 in the lateral ventricles and 2 within the spinal cord). Histologically, SFTs were similar to their soft tissue counterparts. Six tumors (6/18) had densely cellular regions, and 1 tumor showed frankly anaplastic features. All but 3 patients underwent gross total resection, and there were no metastases or tumor-related mortalities during the median follow-up of 40 months. In contrast, there were 15 local recurrences (83%), 5 extracranial metastases (27%), and 4 tumor-related deaths (22%) in the HPC cohort.


CONCLUSIONS
Our study presents the clinicopathologic features of SFT as a distinct entity from both meningioma and HPC. We also present unusual examples of anaplastic, intraventricular, and intramedullary spinal SFTs that expand the clinicopathologic spectrum of these uncommon and sometimes diagnostically difficult neoplasms.
Tihan
Tarik
T
Department of Pathology, The Johns Hopkins University School of Medicine, Baltimore, Md, USA. tihan@itsa.ucsf.edu
Viglione
Michael
M
Rosenblum
Marc K
MK
Olivi
Alessandro
A
Burger
Peter C
PC
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016543:Central Nervous System Neoplasms / Q000175:diagnosis* / Q000532:radiotherapy / Q000601:surgery; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015192:Infratentorial Neoplasms / Q000175:diagnosis / Q000532:radiotherapy / Q000601:surgery; D008297:Male; D008577:Meningeal Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000532:radiotherapy / Q000601:surgery; D008579:Meningioma / Q000175:diagnosis* / Q000401:mortality / Q000532:radiotherapy / Q000556:secondary / Q000601:surgery; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D018218:Neoplasms, Fibrous Tissue / Q000175:diagnosis* / Q000532:radiotherapy / Q000601:surgery; D013120:Spinal Cord Neoplasms / Q000175:diagnosis / Q000532:radiotherapy / Q000601:surgery