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Intramedullary Solitary Fibrous Tumor—A Benign Form of Hemangiopericytoma? Case Report and Review of the Literature
Case Report
Intramedullary Solitary Fibrous Tumor—A Benign Form of Hemangiopericytoma? Case Report and Review of the Literature Markus Bruder1, Dominique Tews2, Michel Mittelbronn2, David Capper3, Volker Seifert1, Gerhard Marquardt1
Key words Hemangiopericytoma - Intramedullary - Neurosurgery - Solitary fibrous tumor - Spinal cord -
Abbreviations and Acronyms HPC: Hemangiopericytoma MRI: Magnetic resonance imaging SFT: Solitary fibrous tumor From the Departments of 1Neurosurgery and 2 Neuropathology, Johann Wolfgang Goethe University, Frankfurt am Main, Germany; and 3Department of Neuropathology, University Hospital Heidelberg and Clinical Cooperation Unit Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany To whom correspondence should be addressed: Markus Bruder, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2015) 84, 1:189.e7-189.e12. http://dx.doi.org/10.1016/j.wneu.2015.02.036 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com
- BACKGROUND:
Solitary fibrous tumors (SFTs) are benign tumors of the soft tissue occurring anywhere in the human body but arise predominantly in the visceral pleura. SFTs of the central nervous system are rare, especially when they occur within the spinal cord.
- CASE
DESCRIPTION: We present a case of an 83-year-old female patient presenting with acute spastic paralysis of the lower extremities after a history of progressive weakness and incontinence. Magnetic resonance imaging (MRI) findings were typical for meningioma, but an intradural, mainly intramedullary tumor was found at the first operation. A second operation was performed under neurophysiological monitoring, and complete removal of the tumor was achieved. Neurological conditions improved after the procedure, but the patient remained paraparetic. Histological and immunohistochemical findings revealed an SFT.
- CONCLUSIONS:
There is evidence that SFTs and hemangiopericytomas (HPCs) are not different entities but should be considered as different graduations of a common spectrum. The extent of resection is a prognostic factor for recurrence-free survival in SFT; therefore we recommend surgery with complete resection whenever possible depending on the results of mandatory intraoperative neurophysiological monitoring in these cases.
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INTRODUCTION Solitary fibrous tumors (SFTs) are mesenchymal tumors first described in 1931 by Klemperer and Rabin as a primary neoplasm arising from the pleura (23). The visceral pleura is still the predominant location of SFTs. Nevertheless, SFTs can arise in the soft tissue anywhere in the body, even in the central nervous system (2, 7, 8, 15, 18, 21, 24, 32, 41-43). The occurrence completely or partially within the spinal cord is rare and has been reported in 16 cases so far to the best of our knowledge (1, 4, 8, 10, 11, 17, 18, 20, 21, 27, 29, 33, 34, 38). Although there are some recurrent cases even after complete resection (3, 4, 11, 21, 27, 38), SFTs of the central nervous system are principally benign tumors that can be treated by surgery alone, as they seem to be insensitive to chemotherapy or radiotherapy (5, 6, 28, 31). However, the histological findings of SFT show many similarities to the more malignant
hemangiopericytoma (HPC), which is also rare in the central nervous system (5, 10, 36, 38). In the past decade more and more pathologists assume a common spectrum of these tumors (5, 28). We present a case of an intramedullary tumor with typical histopathological and immunohistochemical findings for SFT. CASE REPORT An 83-year-old female presented with a 1.5year history of weakness and progressive paresthesia of the left leg. Recent to admission the symptoms had worsened to bilateral spastic paralysis of both legs and bladder incontinence. Further examination revealed 3/5 paresis of the legs, and even with assistance the patient was unable to walk due to uncontrollable spasticity and ataxia of both legs. Sensory testing revealed numbness of the lower left leg. Magnetic resonance imaging (MRI) showed an intraspinal tumor at the level of T8-T9 with a massive compression of the spinal cord.
WORLD NEUROSURGERY 84 [1]: 189.e7-189.e12, JULY 2015
The lesion was slightly hyperintense in T1-weighted images and hypointense in the T2-weighted images and showed a homogeneous gadolinium contrast enhancement (Figure 1). The lesion was suspected to be a meningioma, and an operation was performed rather quickly in order to restore the neurological function. The operation was carried out through a laminectomy of T9 and a partial laminectomy of T8 and T10. An intradural, mainly intramedullary lesion was exposed with an exophytic part without any dural attachment. The lesion had a dense consistence and a whitish color. In the absence of neurophysiological monitoring, as the tumor had been suspected to be extramedullar, we aborted the initial operation after taking a biopsy of the small exophytic part. Neurological deficits already improved slightly after the first operation, most likely because of the decompressing effect due to laminectomy. Histological analysis revealed anSFT. Therefore we performed the resection of
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189.E7
CASE REPORT MARKUS BRUDER ET AL.
INTRAMEDULLARY SOLITARY FIBROUS TUMOR
Figure 1. Magnetic resonance imaging findings with isointense signal in T1 (A), hypointense signal in T2 (B), and homogeneously gadolinium enhancement (C).
the remaining tumor part 9 days later under neurophysiological monitoring conditions. The tumor was well circumscribed but showed some arachnoid invasion on the caudal and medial parts. With the microsurgical technique complete, tumor removal was achieved. The neurological function improved slowly after the operation, and the patient was sent to a rehabilitation center. At that time she was able to stand without assistance. Eight months later motor function of the legs has improved to 4/5 according to Medical Research Council (MRC) motor grading. She is able to walk a few steps but is dependent on a wheelchair for longer distances due to persistent ataxia. Histological Findings Eight fragments of unfixed tissue obtained within the first operation were transferred to the neuropathology department. Fresh frozen, hematoxylin-eosin stained sections of some fragments revealed a relatively dense tumor tissue with spindle-shaped tumor cells arranged in fascicles. The nuclei were oval to elongated lacking increased mitotic activity. There was no necrosis. Remaining parts of the tissue sample were fixed in formalin and embedded in paraffin (Figure 2). Tissue sections showed again a spindle cell tumor with intermingled collagen fiber bundles and a dense reticulin fiber network. Mitoses were rare with less than 1 in 10 high-
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power field (HPF) and no necrosis. Immunohistochemical analysis revealed strong expression of vimentin but was negative for S100 and epithelial membrane antigen (EMA). The tumor displayed a strong nuclear STAT6 staining. There was a patchy immunoreactivity for bcl-2 and CD34. MIB1-labeling was low in most parts of the tissue samples, mostly not exceeding 1%; however, focally the labeling-index increased up to 5%. On the basis of the morphologic and immunohistochemical findings, the tumor was diagnosed as an SFT. The tissue specimen from the second surgery revealed again a spindle cell tumor rich in collagenous connective tissue (Figure 3). Still, mitoses were rare. There was focal necrosis, which we attribute to the first surgery. Furthermore, this tissue specimen displayed large areas of collagen depositions with fibrosis and hyalinization with focal remnants of peripheral nerves, which seemed to be diffusely invaded by the tumor. The immunohistochemical expression pattern corresponded to the tumor tissue of the first surgery and confirmed the diagnosis of a SFT. DISCUSSION SFT is a rare, predominantly benign lesion that can arise anywhere in the soft tissue of the human body. Nevertheless, recurrence is known and malignant behavior of
SFT involving the central nervous system has been reported in a few cases (5, 6, 8, 11, 13, 14, 30, 31, 38, 39). The majority of SFTs of the central nervous system are intracranial, intradural, extraaxial lesions (3). More than a third (34%) occur within the spinal canal, and nearly half of these (49%) are located partially or completely intramedullar (27). However, intramedullary SFTs are still a rare entity. To the best of our knowledge, only 17 cases including the present one have been published so far (1, 4, 8, 10, 11, 17, 18, 20, 21, 27, 29, 33, 34, 38). SFTs of the spinal canal are most often localized in the thoracic spine followed by the cervical spine (11, 18). Of the 17 cases with intramedullary components, half were located cervical and the other half in the thoracic region. The reviewed cases of intramedullary SFT showed no adherence to the dura mater but strong adherence to the pia mater or spinal cord. In these cases the origin is suspected to be the pia mater itself or the perivascular soft tissue (17, 18). All reviewed intramedullary cases were treated surgically, and complete removal was achieved in 79% (Table 1). Despite the fact that SFTs are usually isointense or hypointense in T1-weighted images, the lesion in the present case was slightly hyperintense in T1-weighted images. However, histological examination revealed characteristic findings for SFTs. Signal intensity in T2-weighted images is typically hypointense due to hypercellular
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CASE REPORT MARKUS BRUDER ET AL.
INTRAMEDULLARY SOLITARY FIBROUS TUMOR
Figure 2. Spindle-shaped tumor cells arranged in fascicles (A, hematoxylin and eosin) with patchy immunoreactivity for CD34 (B) and bcl-2 (C). Strong nuclear expression of STAT6 (D). Areas with an increased labeling index for Ki67 (MIB-1 antibody) (E).
areas or hypocellular but collagenous or calcified areas within the tumor (11, 12, 18, 21, 22, 26, 27, 37). SFTs show a homogenous gadolinium enhancement in nearly every case (see Table 1). These MRI features make it difficult to distinguish SFTs from meningioma, schwannoma, and other intradural and even intramedullary tumor entities like astrocytoma or ependymoma (3, 11, 17, 18, 21, 27, 31). Because of MRI, the initial diagnosis in the presented case was meningioma, although intraoperative findings revealed the main part of the tumor to be located intramedullary without dural attachment. This misleading preoperative assumption is known for SFTs even with intramedullary parts (1, 27, 38).
In 23% of the reviewed intramedullar cases the lesion was preoperatively suspected to be extramedullar, and in another 23% of cases discrimination between intramedullary and extramedullary was not possible by MRI (see Table 1). SFT is a spindle cell tumor characterized by a combination of alternating hypocellular collagenic and hypercellular areas showing branching vessels (5) with similarities to fibrous meningioma (19) and hemangiopericytoma (40). SFTs are typically positive for CD34 and can be distinguished from schwannoma and meningioma via negative reaction to S100 and EMA in immunohistochemistry (5, 11, 18, 21, 27). Furthermore, SFTs are
positive for vimentin (11, 18, 21) and bcl-2 (9, 11, 27). MIB-1 labeling is low (3, 5, 18). It is difficult to distinguish SFTs from HPCs via MRI, histology, or immunohistochemistry as both show many overlapping features (5, 10, 38). Even though HPC is a rare tumor of the central nervous system, intramedullary occurrence has been described in a few cases (36). In contrast to SFTs, HPCs are typically hypercellular with a higher mitotic rate and presence of cell atypia, show CD34positivity in 33%e100%, and are highly vascularized (5, 6, 16, 18, 25, 38). A cellular form of SFT that is indistinguishable from HPC has been described. In the past decade many pathologists have proposed a
Figure 3. Tissue specimen of the second surgery with a spindle cell tumor with abundant collagenous connective tissue (A) and focal necrosis (B). Focally, S100-positive remnants of an invaded peripheral nerve (C).
WORLD NEUROSURGERY 84 [1]: 189.e7-189.e12, JULY 2015
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189.E9
MRI Findings
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Author
Sex/ Age
Carneiro et al. 1996 (8) m/50
Intraoperative Findings
Loc.
Symptoms
T1
T2
T1 D KM
Susp. Location
-
Cono-caudal syndrome
-
-
-
-
Surgery
-
-
-
EM
Surgery
IM
Def. Treatment Location
Defined
Adhesion
Dural attachm.
Months
-
Leptomenings
No
60
Improved
Yes
Total
Yes
-
No
24
Improved
No
-
Yes
-
-
-
-
-
No
18
-
No
-
-
-
-
EoR
IM þ EM Partial
Alston et al. 1997 (1)
m/47 T 4-5 BrowneSéquard syndrome
Kanahara et al. 1999 (20)
m/62 C 6-7 Leg numbness
Hypo Hypo Slight
EM
Surgery
IM þ EM
Mordani et al. 2000 (29)
m/33 C 5
Iso
Hypo Homo
IM
Surgery
IM
Total
Yes
-
Hypo Homo
-
Surgery
IM
-
Yes
-
Hypo Homo
IM
-
Yes
Tihan et al. 2003 (38) Tihan et al. 2003 (38)
Cervical myelopathy
-
-
-
-
-
-
No -
Surgery Surgery
IM þ EM Subtotal
No
Spinal cord
Hypo Homo
IM þ EM
Surgery
IM þ EM Total
Yes
Hypo Homo
-
Surgery
IM þ EM Total
Hypo Hypo Homo
-
Surgery
IM
-
IM
Surgery
Hypo Homo
IM
Surgery
Unclear
Surgery
IM þ EM Total
-
IM
Surgery
IM þ EM Total
-
Hypo Hypo Homo
Unclear
Surgery
T 9- Thoracic myelopathy 10
Hypo Hypo Homo
IM þ EM
Surgery
IM þ EM Partial
No
T 8-9 Paralysis and incontinence
Hyper Hypo Homo
EM
Surgery
IM þ EM Total
Yes
m/64 T 2-3 Brown-Séquard syndrome
Hypo Hypo Homo
Bohinski et al. 2004 (4)
f/49
Iso
Jallo et al. 2005 (18)
m/41 C 6-7 Cervical myelopathy
Iso
Jallo et al. 2005 (18)
m/17 T 5-6 Spastic paraparesis
Pizzolitto et al. 2005 (33)
m/47 C 4
Cervical myelopathy
Ishii et al. 2009 (17)
f/63
C5
Weakness upper extremity
Ciappetta et al. 2010 (10)
f/75
T 6-7 Paralysis lower extremity
Fargen et al. 2011 (11)
f/28
C 2-3 Lower extremity numbness
Mariniello et al. 2012 (27)
m/75 T 6-7 Thoracic myelopathy
Robert et al. 2014 (34)
f/49
Present case
f/83
C4
Neck pain, arm paresthesia
Iso
-
Hypo Hypo Homo -
-
Homo
-
-
-
6
No
No
Yes
No
Total
Yes
Spinal cord
IM
Total
-
IM
Total
Yes
IM
Total
-
-
Neurol. outcome
-
Rec.
-
Improved
No
10
Stable
No
-
42
Improved
No
-
19
Yes
No
-
12
Improved
No
Pia mater
No
14
No NL deficits
No
No
No
24
No NL deficits
No
No
24
No NL deficits
No
No
12
No NL deficits
No
-
-
6
No NL deficits
No
Leptomeninges
No
8
Improved
No
-
Spinal cord
CASE REPORT
m, male; f, female; T, thoracic; C, cervical; hypo, hypointense; iso, isointense; homo, homogeneous; IM, intramedullar; EM, extramedullar; NL, neurological; Loc., Location; Susp., suspected; Def., definitive; EoR, extent of resection; attachm., attachment; Mths., months; Rec., recurrence; Neurol., neurological.
INTRAMEDULLARY SOLITARY FIBROUS TUMOR
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2015.02.036
Unclear
Kawamura et al. 2004 (21)
Follow-up
MARKUS BRUDER ET AL.
189.E10
Table 1. Cases of Intramedullary Solitary Fibrous Tumor in Literature
CASE REPORT MARKUS BRUDER ET AL.
common spectrum of these tumors (5, 28). Because SFT progression to HPC-like tumors and HPC recurrence as SFTs have been reported, Bouvier et al. (5) suggested that the artificial separation between SFT and HPC is a reflection of histological appearance and does not indicate two distinct entities. This suggestion was strongly supported by the findings of Schweizer et al. (35), who reported a similar NAB2-STAT6 fusion in the DNA of HPC and SFT. Some authors have already recommended clinical treatment and follow-up strategies according to HPC treatment (6). However, SFTs are predominantly benign. Anaplastic HPCs are malignant neoplasms with higher recurrence rates, with a tendency for meningeal spreading, and distant metastases (5, 38) necessitating a more radical treatment. The extent of resection is a prognostic factor for recurrence-free survival in SFT, and surgery is recommended. Complete removal of the tumor is possible even in SFT with intramedullary components. Resection should be performed carefully under neurophysiological monitoring because most SFTs are well defined (see Table 1) but can present with a firm spinal cord attachment (5, 27). Thereby a favorable outcome is achievable. Recurrence is rare after gross total removal but has been reported after subtotal resection despite subsequent radiotherapy (3, 4, 11, 21, 27, 38). Recurrence of SFT of the central nervous system can occur several years after clinical manifestation (8, 30, 38, 40), and drop metastasis after complete resection has been described (34). Chemotherapy has been administered in some recurrent cases, but so far there is no evidence of a therapeutic effect (6). SFTs seem to be insensitive for radiotherapy and chemotherapy (5, 28, 31). As other authors already have proposed (10, 13, 17, 28), we suggest a careful clinical and radiological long-term follow-up in cases of SFT of the central nervous system. CONCLUSION Intramedullary SFTs are rare entities with predominantly benign behavior. Considering histopathological examination, SFTs and HPCs seem to be different graduations of the same tumor entity. The extent of resection is a prognostic factor for
INTRAMEDULLARY SOLITARY FIBROUS TUMOR
recurrence-free survival. Therefore surgery is recommended and intraoperative neurophysiological monitoring is mandatory in intramedullary cases. Complete resection should be aspired whenever possible depending on monitoring results. REFERENCES 1. Alston SR, Francel PC, Jane JA Jr: Solitary fibrous tumor of the spinal cord. Am J Surg Pathol 21: 477-483, 1997. 2. Barnoud R, Arvieux C, Pasquier D, Pasquier B, Letoublon C: Solitary fibrous tumour of the liver with CD34 expression. Histopathology 28:551-554, 1996. 3. Bisceglia M, Dimitri L, Giannatempo G, Carotenuto V, Bianco M, Monte V, D’Angelo V, Magro G: Solitary fibrous tumor of the central nervous system: report of an additional 5 cases with comprehensive literature review. Int J Surg Pathol 19:476-486, 2011. 4. Bohinski RJ, Mendel E, Aldape KD, Rhines LD: Intramedullary and extramedullary solitary fibrous tumor of the cervical spine. Case report and review of the literature. J Neurosurg 100:358-363, 2004. 5. Bouvier C, Metellus P, de Paula AM, Vasiljevic A, Jouvet A, Guyotat J, Mokhtari K, Varlet P, Dufour H, Figarella-Branger D: Solitary fibrous tumors and hemangiopericytomas of the meninges: overlapping pathological features and common prognostic factors suggest the same spectrum of tumors. Brain Pathol 22:511-521, 2012. 6. Brigui M, Aldea S, Bernier M, Bennis S, Mireau E, Gaillard S: Two patients with a solitary fibrous tumor of the thoracic spinal cord. J Clin Neurosci 20:317-319, 2013. 7. Cameselle-Teijeiro J, Varela-Duran J, Fonseca E, Villanueva JP, Sobrinho-Simoes M: Solitary fibrous tumor of the thyroid. Am J Clin Pathol 101: 535-538, 1994. 8. Carneiro SS, Scheithauer BW, Nascimento AG, Hirose T, Davis DH: Solitary fibrous tumor of the meninges: a lesion distinct from fibrous meningioma. A clinicopathologic and immunohistochemical study. Am J Clin Pathol 106:217-224, 1996. 9. Chilosi M, Facchettti F, Dei Tos AP, Lestani M, Morassi ML, Martignoni G, Sorio C, Benedetti A, Morelli L, Doglioni C, Barberis M, Menestrina F, Viale, G: bcl-2 expression in pleural and extrapleural solitary fibrous tumours. J Pathol 181: 362-367, 1997. 10. Ciappetta P, D’Urso PI, Cimmino A, Ingravallo G, Rossi R, Colamaria A, D’Urso OF: Intramedullary solitary fibrous tumor of dorsal spinal cord. Neuropathology 30:273-278, 2010. 11. Fargen KM, Opalach KJ, Wakefield D, Jacob RP, Yachnis AT, Lister JR: The central nervous system solitary fibrous tumor: a review of clinical, imaging and pathologic findings among all reported cases from 1996 to 2010. Clin Neurol Neurosurg 113:703-710, 2011.
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12. Ferretti GR, Chiles C, Choplin RH, Coulomb M: Localized benign fibrous tumors of the pleura. AJR Am J Roentgenol 169:683-686, 1997. 13. Gessi M, Gielen GH, Roeder-Geyer ED, Sommer C, Vieth M, Braun V, Kuchelmeister K, Pietsch T: Extracranial metastasizing solitary fibrous tumors (SFT) of meninges: histopathological features of a case with long-term follow-up. Neuropathology 33:68-74, 2013. 14. Hanau CA, Miettinen M: Solitary fibrous tumor: histological and immunohistochemical spectrum of benign and malignant variants presenting at different sites. Hum Pathol 26:440-449, 1995. 15. Hasegawa T, Matsuno Y, Shimoda T, Hasegawa F, Sano T, Hirohashi S: Extrathoracic solitary fibrous tumors: their histological variability and potentially aggressive behavior. Hum Pathol 30: 1464-1473, 1999. 16. Hayashi Y, Uchiyama N, Hayashi Y, Nakada M, Iwato M, Kita D, Higashi R, Hirota Y, Kai Y, Kuratsu J, Hamada J: A reevaluation of the primary diagnosis of hemangiopericytoma and the clinical importance of differential diagnosis from solitary fibrous tumor of the central nervous system. Clin Neurol Neurosurg 111:34-38, 2009. 17. Ishii K, Nakamura M, Matsumoto M, Mukai M, Toyama Y, Chiba K: Intramedullary solitary fibrous tumor of the spinal cord. J Orthop Sci 14: 450-454, 2009. 18. Jallo GI, Roonprapunt C, Kothbauer K, Freed D, Allen J, Epstein F: Spinal solitary fibrous tumors: a series of four patients: case report. Neurosurgery 57:E195; discussion E195, 2005. 19. Johnson MD, Powell SZ, Boyer PJ, Weil RJ, Moots PL: Dural lesions mimicking meningiomas. Hum Pathol 33:1211-1226, 2002. 20. Kanahara T, Hirokawa M, Shimizu M, Terayama K, Nakamura E, Hino Y, Mikawa Y, Manabe T: Solitary fibrous tumor of the spinal cord. Report of a case with scrape cytology. Acta Cytol 43:425-428, 1999. 21. Kawamura M, Izawa K, Hosono N, Hirano H: Solitary fibrous tumor of the spinal cord: case report and review of the literature. Neurosurgery 55:433, 2004. 22. Kim TA, Brunberg JA, Pearson JP, Ross DA: Solitary fibrous tumor of the paranasal sinuses: CT and MR appearance. AJNR Am J Neuroradiol 17:1767-1772, 1996. 23. Klemperer P, Rabin CB: Primary neoplasms of the pleura: a report of five cases. Arch Pathol Lab Med 11:385-412, 1931. 24. Kottke-Marchant K, Hart WR, Broughan T: Localized fibrous tumor (localized fibrous mesothelioma) of the liver. Cancer 64:1096-1102, 1989. 25. Louis DN, Ohgaki H, Wiestler OD, Cavenee WK, Burger PC, Jouvet A, Scheithauer BW, Kleihues P: The 2007 WHO classification of tumours of the central nervous system. Acta Neuropathol 114: 97-109, 2007. 26. Malek AM, Weller SJ, Price DL Jr, Madsen JR: Solitary fibrous tumor presenting as a
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symptomatic intraspinal mass: case report. Neurosurgery 40:844-847; discussion 847, 1997. 27. Mariniello G, Napoli M, Russo C, Briganti F, Giamundo A, Maiuri F, Del Basso De Caro ML: MRI features of spinal solitary fibrous tumors. A report of two cases and literature review. Neuroradiol J 25:610-616, 2012. 28. Metellus P, Bouvier C, Guyotat J, Fuentes S, Jouvet A, Vasiljevic A, Giorgi R, Dufour H, Grisoli F, Figarella-Branger D: Solitary fibrous tumors of the central nervous system: clinicopathological and therapeutic considerations of 18 cases. Neurosurgery 60:715-722; discussion 722, 2007. 29. Mordani JP, Haq IU, Singh J: Solitary fibrous tumour of the spinal cord. Neuroradiology 42: 679-681, 2000. 30. Munoz E, Prat A, Adamo B, Peralta S, Ramon y Cajal S, Valverde C: A rare case of malignant solitary fibrous tumor of the spinal cord. Spine 33: E397-E399, 2008. 31. Nagano A, Ohno T, Nishimoto Y, Oshima K, Shimizu K: Malignant solitary fibrous tumor of the lumbar spinal root mimicking schwannoma: a case report. Spine J 14:e17-e20, 2014. 32. O’Connell JX, Logan PM, Beauchamp CP: Solitary fibrous tumor of the periosteum. Hum Pathol 26: 460-462, 1995. 33. Pizzolitto S, Falconieri G, Demaglio G: Solitary fibrous tumor of the spinal cord: a clinicopathologic study of two cases. Ann Diagn Pathol 8: 268-275, 2004.
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34. Robert T, Duc C, San Millan Ruiz D, Morard M: Solitary fibrous tumour with intramedullary component: case report and review of the literature. Neurol Neurochir Pol 48:144-149, 2014. 35. Schweizer L, Koelsche C, Sahm F, Piro RM, Capper D, Reuss DE, Pusch S, Habel A, Meyer J, Gock T, Jones DT, Mawrin C, Schittenhelm J, Becker A, Heim S, Simon M, Herold-Mende C, Mechtersheimer G, Paulus W, Konig R, Wiestler OD, Pfister SM, Deimling A von: Meningeal hemangiopericytoma and solitary fibrous tumors carry the NAB2-STAT6 fusion and can be diagnosed by nuclear expression of STAT6 protein. Acta Neuropathol 125:651-658, 2013. 36. Shirzadi A, Drazin D, Gates M, Shirzadi N, Bannykh S, Fan X, Hunt L, Baron EM, King WA, Kim TT, Johnson JP: Surgical management of primary spinal hemangiopericytomas: an institutional case series and review of the literature. Eur Spine J 22:S450-S459, 2013. 37. Tateishi U, Nishihara H, Morikawa T, Miyasaka K: Solitary fibrous tumor of the pleura: MR appearance and enhancement pattern. J Comput Assist Tomogr 26:174-179, 2002. 38. Tihan T, Viglione M, Rosenblum MK, Olivi A, Burger PC: Solitary fibrous tumors in the central nervous system. A clinicopathologic review of 18 cases and comparison to meningeal hemangiopericytomas. Arch Pathol Lab Med 127:432-439, 2003. 39. Vallat-Decouvelaere AV, Dry SM, Fletcher CD: Atypical and malignant solitary fibrous tumors in extrathoracic locations: evidence of their comparability
to intra-thoracic tumors. Am J Surg Pathol 22: 1501-1511, 1998. 40. Vorster SJ, Prayson RA, Lee JH: Solitary fibrous tumor of the thoracic spine. Case report and review of the literature. J Neurosurg 92 (2 Suppl): 217-220, 2000. 41. Wang H, Chen P, Zhao W, Shi L, Gu X, Xu Q: Clinicopathological findings in a case series of abdominopelvic solitary fibrous tumors. Oncol Lett 7:1067-1072, 2014. 42. Westra WH, Gerald WL, Rosai J: Solitary fibrous tumor. Consistent CD34 immunoreactivity and occurrence in the orbit. Am J Surg Pathol 18 (10): 992-998, 1994. 43. Witkin GB, Rosai J: Solitary fibrous tumor of the upper respiratory tract. A report of six cases. Am J Surg Pathol 15:842-848, 1991.
Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Received 23 January 2015; accepted 26 February 2015 Citation: World Neurosurg. (2015) 84, 1:189.e7-189.e12. http://dx.doi.org/10.1016/j.wneu.2015.02.036 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2015 Elsevier Inc. All rights reserved.
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2015.02.036
Intramedullary Solitary Fibrous Tumor—A Benign Form of Hemangiopericytoma? Case Report and Review of the Literature Markus Bruder1, Dominique Tews2, Michel Mittelbronn2, David Capper3, Volker Seifert1, Gerhard Marquardt1
Key words Hemangiopericytoma - Intramedullary - Neurosurgery - Solitary fibrous tumor - Spinal cord -
Abbreviations and Acronyms HPC: Hemangiopericytoma MRI: Magnetic resonance imaging SFT: Solitary fibrous tumor From the Departments of 1Neurosurgery and 2 Neuropathology, Johann Wolfgang Goethe University, Frankfurt am Main, Germany; and 3Department of Neuropathology, University Hospital Heidelberg and Clinical Cooperation Unit Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany To whom correspondence should be addressed: Markus Bruder, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2015) 84, 1:189.e7-189.e12. http://dx.doi.org/10.1016/j.wneu.2015.02.036 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com
- BACKGROUND:
Solitary fibrous tumors (SFTs) are benign tumors of the soft tissue occurring anywhere in the human body but arise predominantly in the visceral pleura. SFTs of the central nervous system are rare, especially when they occur within the spinal cord.
- CASE
DESCRIPTION: We present a case of an 83-year-old female patient presenting with acute spastic paralysis of the lower extremities after a history of progressive weakness and incontinence. Magnetic resonance imaging (MRI) findings were typical for meningioma, but an intradural, mainly intramedullary tumor was found at the first operation. A second operation was performed under neurophysiological monitoring, and complete removal of the tumor was achieved. Neurological conditions improved after the procedure, but the patient remained paraparetic. Histological and immunohistochemical findings revealed an SFT.
- CONCLUSIONS:
There is evidence that SFTs and hemangiopericytomas (HPCs) are not different entities but should be considered as different graduations of a common spectrum. The extent of resection is a prognostic factor for recurrence-free survival in SFT; therefore we recommend surgery with complete resection whenever possible depending on the results of mandatory intraoperative neurophysiological monitoring in these cases.
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INTRODUCTION Solitary fibrous tumors (SFTs) are mesenchymal tumors first described in 1931 by Klemperer and Rabin as a primary neoplasm arising from the pleura (23). The visceral pleura is still the predominant location of SFTs. Nevertheless, SFTs can arise in the soft tissue anywhere in the body, even in the central nervous system (2, 7, 8, 15, 18, 21, 24, 32, 41-43). The occurrence completely or partially within the spinal cord is rare and has been reported in 16 cases so far to the best of our knowledge (1, 4, 8, 10, 11, 17, 18, 20, 21, 27, 29, 33, 34, 38). Although there are some recurrent cases even after complete resection (3, 4, 11, 21, 27, 38), SFTs of the central nervous system are principally benign tumors that can be treated by surgery alone, as they seem to be insensitive to chemotherapy or radiotherapy (5, 6, 28, 31). However, the histological findings of SFT show many similarities to the more malignant
hemangiopericytoma (HPC), which is also rare in the central nervous system (5, 10, 36, 38). In the past decade more and more pathologists assume a common spectrum of these tumors (5, 28). We present a case of an intramedullary tumor with typical histopathological and immunohistochemical findings for SFT. CASE REPORT An 83-year-old female presented with a 1.5year history of weakness and progressive paresthesia of the left leg. Recent to admission the symptoms had worsened to bilateral spastic paralysis of both legs and bladder incontinence. Further examination revealed 3/5 paresis of the legs, and even with assistance the patient was unable to walk due to uncontrollable spasticity and ataxia of both legs. Sensory testing revealed numbness of the lower left leg. Magnetic resonance imaging (MRI) showed an intraspinal tumor at the level of T8-T9 with a massive compression of the spinal cord.
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The lesion was slightly hyperintense in T1-weighted images and hypointense in the T2-weighted images and showed a homogeneous gadolinium contrast enhancement (Figure 1). The lesion was suspected to be a meningioma, and an operation was performed rather quickly in order to restore the neurological function. The operation was carried out through a laminectomy of T9 and a partial laminectomy of T8 and T10. An intradural, mainly intramedullary lesion was exposed with an exophytic part without any dural attachment. The lesion had a dense consistence and a whitish color. In the absence of neurophysiological monitoring, as the tumor had been suspected to be extramedullar, we aborted the initial operation after taking a biopsy of the small exophytic part. Neurological deficits already improved slightly after the first operation, most likely because of the decompressing effect due to laminectomy. Histological analysis revealed anSFT. Therefore we performed the resection of
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CASE REPORT MARKUS BRUDER ET AL.
INTRAMEDULLARY SOLITARY FIBROUS TUMOR
Figure 1. Magnetic resonance imaging findings with isointense signal in T1 (A), hypointense signal in T2 (B), and homogeneously gadolinium enhancement (C).
the remaining tumor part 9 days later under neurophysiological monitoring conditions. The tumor was well circumscribed but showed some arachnoid invasion on the caudal and medial parts. With the microsurgical technique complete, tumor removal was achieved. The neurological function improved slowly after the operation, and the patient was sent to a rehabilitation center. At that time she was able to stand without assistance. Eight months later motor function of the legs has improved to 4/5 according to Medical Research Council (MRC) motor grading. She is able to walk a few steps but is dependent on a wheelchair for longer distances due to persistent ataxia. Histological Findings Eight fragments of unfixed tissue obtained within the first operation were transferred to the neuropathology department. Fresh frozen, hematoxylin-eosin stained sections of some fragments revealed a relatively dense tumor tissue with spindle-shaped tumor cells arranged in fascicles. The nuclei were oval to elongated lacking increased mitotic activity. There was no necrosis. Remaining parts of the tissue sample were fixed in formalin and embedded in paraffin (Figure 2). Tissue sections showed again a spindle cell tumor with intermingled collagen fiber bundles and a dense reticulin fiber network. Mitoses were rare with less than 1 in 10 high-
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power field (HPF) and no necrosis. Immunohistochemical analysis revealed strong expression of vimentin but was negative for S100 and epithelial membrane antigen (EMA). The tumor displayed a strong nuclear STAT6 staining. There was a patchy immunoreactivity for bcl-2 and CD34. MIB1-labeling was low in most parts of the tissue samples, mostly not exceeding 1%; however, focally the labeling-index increased up to 5%. On the basis of the morphologic and immunohistochemical findings, the tumor was diagnosed as an SFT. The tissue specimen from the second surgery revealed again a spindle cell tumor rich in collagenous connective tissue (Figure 3). Still, mitoses were rare. There was focal necrosis, which we attribute to the first surgery. Furthermore, this tissue specimen displayed large areas of collagen depositions with fibrosis and hyalinization with focal remnants of peripheral nerves, which seemed to be diffusely invaded by the tumor. The immunohistochemical expression pattern corresponded to the tumor tissue of the first surgery and confirmed the diagnosis of a SFT. DISCUSSION SFT is a rare, predominantly benign lesion that can arise anywhere in the soft tissue of the human body. Nevertheless, recurrence is known and malignant behavior of
SFT involving the central nervous system has been reported in a few cases (5, 6, 8, 11, 13, 14, 30, 31, 38, 39). The majority of SFTs of the central nervous system are intracranial, intradural, extraaxial lesions (3). More than a third (34%) occur within the spinal canal, and nearly half of these (49%) are located partially or completely intramedullar (27). However, intramedullary SFTs are still a rare entity. To the best of our knowledge, only 17 cases including the present one have been published so far (1, 4, 8, 10, 11, 17, 18, 20, 21, 27, 29, 33, 34, 38). SFTs of the spinal canal are most often localized in the thoracic spine followed by the cervical spine (11, 18). Of the 17 cases with intramedullary components, half were located cervical and the other half in the thoracic region. The reviewed cases of intramedullary SFT showed no adherence to the dura mater but strong adherence to the pia mater or spinal cord. In these cases the origin is suspected to be the pia mater itself or the perivascular soft tissue (17, 18). All reviewed intramedullary cases were treated surgically, and complete removal was achieved in 79% (Table 1). Despite the fact that SFTs are usually isointense or hypointense in T1-weighted images, the lesion in the present case was slightly hyperintense in T1-weighted images. However, histological examination revealed characteristic findings for SFTs. Signal intensity in T2-weighted images is typically hypointense due to hypercellular
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CASE REPORT MARKUS BRUDER ET AL.
INTRAMEDULLARY SOLITARY FIBROUS TUMOR
Figure 2. Spindle-shaped tumor cells arranged in fascicles (A, hematoxylin and eosin) with patchy immunoreactivity for CD34 (B) and bcl-2 (C). Strong nuclear expression of STAT6 (D). Areas with an increased labeling index for Ki67 (MIB-1 antibody) (E).
areas or hypocellular but collagenous or calcified areas within the tumor (11, 12, 18, 21, 22, 26, 27, 37). SFTs show a homogenous gadolinium enhancement in nearly every case (see Table 1). These MRI features make it difficult to distinguish SFTs from meningioma, schwannoma, and other intradural and even intramedullary tumor entities like astrocytoma or ependymoma (3, 11, 17, 18, 21, 27, 31). Because of MRI, the initial diagnosis in the presented case was meningioma, although intraoperative findings revealed the main part of the tumor to be located intramedullary without dural attachment. This misleading preoperative assumption is known for SFTs even with intramedullary parts (1, 27, 38).
In 23% of the reviewed intramedullar cases the lesion was preoperatively suspected to be extramedullar, and in another 23% of cases discrimination between intramedullary and extramedullary was not possible by MRI (see Table 1). SFT is a spindle cell tumor characterized by a combination of alternating hypocellular collagenic and hypercellular areas showing branching vessels (5) with similarities to fibrous meningioma (19) and hemangiopericytoma (40). SFTs are typically positive for CD34 and can be distinguished from schwannoma and meningioma via negative reaction to S100 and EMA in immunohistochemistry (5, 11, 18, 21, 27). Furthermore, SFTs are
positive for vimentin (11, 18, 21) and bcl-2 (9, 11, 27). MIB-1 labeling is low (3, 5, 18). It is difficult to distinguish SFTs from HPCs via MRI, histology, or immunohistochemistry as both show many overlapping features (5, 10, 38). Even though HPC is a rare tumor of the central nervous system, intramedullary occurrence has been described in a few cases (36). In contrast to SFTs, HPCs are typically hypercellular with a higher mitotic rate and presence of cell atypia, show CD34positivity in 33%e100%, and are highly vascularized (5, 6, 16, 18, 25, 38). A cellular form of SFT that is indistinguishable from HPC has been described. In the past decade many pathologists have proposed a
Figure 3. Tissue specimen of the second surgery with a spindle cell tumor with abundant collagenous connective tissue (A) and focal necrosis (B). Focally, S100-positive remnants of an invaded peripheral nerve (C).
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MRI Findings
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Author
Sex/ Age
Carneiro et al. 1996 (8) m/50
Intraoperative Findings
Loc.
Symptoms
T1
T2
T1 D KM
Susp. Location
-
Cono-caudal syndrome
-
-
-
-
Surgery
-
-
-
EM
Surgery
IM
Def. Treatment Location
Defined
Adhesion
Dural attachm.
Months
-
Leptomenings
No
60
Improved
Yes
Total
Yes
-
No
24
Improved
No
-
Yes
-
-
-
-
-
No
18
-
No
-
-
-
-
EoR
IM þ EM Partial
Alston et al. 1997 (1)
m/47 T 4-5 BrowneSéquard syndrome
Kanahara et al. 1999 (20)
m/62 C 6-7 Leg numbness
Hypo Hypo Slight
EM
Surgery
IM þ EM
Mordani et al. 2000 (29)
m/33 C 5
Iso
Hypo Homo
IM
Surgery
IM
Total
Yes
-
Hypo Homo
-
Surgery
IM
-
Yes
-
Hypo Homo
IM
-
Yes
Tihan et al. 2003 (38) Tihan et al. 2003 (38)
Cervical myelopathy
-
-
-
-
-
-
No -
Surgery Surgery
IM þ EM Subtotal
No
Spinal cord
Hypo Homo
IM þ EM
Surgery
IM þ EM Total
Yes
Hypo Homo
-
Surgery
IM þ EM Total
Hypo Hypo Homo
-
Surgery
IM
-
IM
Surgery
Hypo Homo
IM
Surgery
Unclear
Surgery
IM þ EM Total
-
IM
Surgery
IM þ EM Total
-
Hypo Hypo Homo
Unclear
Surgery
T 9- Thoracic myelopathy 10
Hypo Hypo Homo
IM þ EM
Surgery
IM þ EM Partial
No
T 8-9 Paralysis and incontinence
Hyper Hypo Homo
EM
Surgery
IM þ EM Total
Yes
m/64 T 2-3 Brown-Séquard syndrome
Hypo Hypo Homo
Bohinski et al. 2004 (4)
f/49
Iso
Jallo et al. 2005 (18)
m/41 C 6-7 Cervical myelopathy
Iso
Jallo et al. 2005 (18)
m/17 T 5-6 Spastic paraparesis
Pizzolitto et al. 2005 (33)
m/47 C 4
Cervical myelopathy
Ishii et al. 2009 (17)
f/63
C5
Weakness upper extremity
Ciappetta et al. 2010 (10)
f/75
T 6-7 Paralysis lower extremity
Fargen et al. 2011 (11)
f/28
C 2-3 Lower extremity numbness
Mariniello et al. 2012 (27)
m/75 T 6-7 Thoracic myelopathy
Robert et al. 2014 (34)
f/49
Present case
f/83
C4
Neck pain, arm paresthesia
Iso
-
Hypo Hypo Homo -
-
Homo
-
-
-
6
No
No
Yes
No
Total
Yes
Spinal cord
IM
Total
-
IM
Total
Yes
IM
Total
-
-
Neurol. outcome
-
Rec.
-
Improved
No
10
Stable
No
-
42
Improved
No
-
19
Yes
No
-
12
Improved
No
Pia mater
No
14
No NL deficits
No
No
No
24
No NL deficits
No
No
24
No NL deficits
No
No
12
No NL deficits
No
-
-
6
No NL deficits
No
Leptomeninges
No
8
Improved
No
-
Spinal cord
CASE REPORT
m, male; f, female; T, thoracic; C, cervical; hypo, hypointense; iso, isointense; homo, homogeneous; IM, intramedullar; EM, extramedullar; NL, neurological; Loc., Location; Susp., suspected; Def., definitive; EoR, extent of resection; attachm., attachment; Mths., months; Rec., recurrence; Neurol., neurological.
INTRAMEDULLARY SOLITARY FIBROUS TUMOR
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Unclear
Kawamura et al. 2004 (21)
Follow-up
MARKUS BRUDER ET AL.
189.E10
Table 1. Cases of Intramedullary Solitary Fibrous Tumor in Literature
CASE REPORT MARKUS BRUDER ET AL.
common spectrum of these tumors (5, 28). Because SFT progression to HPC-like tumors and HPC recurrence as SFTs have been reported, Bouvier et al. (5) suggested that the artificial separation between SFT and HPC is a reflection of histological appearance and does not indicate two distinct entities. This suggestion was strongly supported by the findings of Schweizer et al. (35), who reported a similar NAB2-STAT6 fusion in the DNA of HPC and SFT. Some authors have already recommended clinical treatment and follow-up strategies according to HPC treatment (6). However, SFTs are predominantly benign. Anaplastic HPCs are malignant neoplasms with higher recurrence rates, with a tendency for meningeal spreading, and distant metastases (5, 38) necessitating a more radical treatment. The extent of resection is a prognostic factor for recurrence-free survival in SFT, and surgery is recommended. Complete removal of the tumor is possible even in SFT with intramedullary components. Resection should be performed carefully under neurophysiological monitoring because most SFTs are well defined (see Table 1) but can present with a firm spinal cord attachment (5, 27). Thereby a favorable outcome is achievable. Recurrence is rare after gross total removal but has been reported after subtotal resection despite subsequent radiotherapy (3, 4, 11, 21, 27, 38). Recurrence of SFT of the central nervous system can occur several years after clinical manifestation (8, 30, 38, 40), and drop metastasis after complete resection has been described (34). Chemotherapy has been administered in some recurrent cases, but so far there is no evidence of a therapeutic effect (6). SFTs seem to be insensitive for radiotherapy and chemotherapy (5, 28, 31). As other authors already have proposed (10, 13, 17, 28), we suggest a careful clinical and radiological long-term follow-up in cases of SFT of the central nervous system. CONCLUSION Intramedullary SFTs are rare entities with predominantly benign behavior. Considering histopathological examination, SFTs and HPCs seem to be different graduations of the same tumor entity. The extent of resection is a prognostic factor for
INTRAMEDULLARY SOLITARY FIBROUS TUMOR
recurrence-free survival. Therefore surgery is recommended and intraoperative neurophysiological monitoring is mandatory in intramedullary cases. Complete resection should be aspired whenever possible depending on monitoring results. REFERENCES 1. Alston SR, Francel PC, Jane JA Jr: Solitary fibrous tumor of the spinal cord. Am J Surg Pathol 21: 477-483, 1997. 2. Barnoud R, Arvieux C, Pasquier D, Pasquier B, Letoublon C: Solitary fibrous tumour of the liver with CD34 expression. Histopathology 28:551-554, 1996. 3. Bisceglia M, Dimitri L, Giannatempo G, Carotenuto V, Bianco M, Monte V, D’Angelo V, Magro G: Solitary fibrous tumor of the central nervous system: report of an additional 5 cases with comprehensive literature review. Int J Surg Pathol 19:476-486, 2011. 4. Bohinski RJ, Mendel E, Aldape KD, Rhines LD: Intramedullary and extramedullary solitary fibrous tumor of the cervical spine. Case report and review of the literature. J Neurosurg 100:358-363, 2004. 5. Bouvier C, Metellus P, de Paula AM, Vasiljevic A, Jouvet A, Guyotat J, Mokhtari K, Varlet P, Dufour H, Figarella-Branger D: Solitary fibrous tumors and hemangiopericytomas of the meninges: overlapping pathological features and common prognostic factors suggest the same spectrum of tumors. Brain Pathol 22:511-521, 2012. 6. Brigui M, Aldea S, Bernier M, Bennis S, Mireau E, Gaillard S: Two patients with a solitary fibrous tumor of the thoracic spinal cord. J Clin Neurosci 20:317-319, 2013. 7. Cameselle-Teijeiro J, Varela-Duran J, Fonseca E, Villanueva JP, Sobrinho-Simoes M: Solitary fibrous tumor of the thyroid. Am J Clin Pathol 101: 535-538, 1994. 8. Carneiro SS, Scheithauer BW, Nascimento AG, Hirose T, Davis DH: Solitary fibrous tumor of the meninges: a lesion distinct from fibrous meningioma. A clinicopathologic and immunohistochemical study. Am J Clin Pathol 106:217-224, 1996. 9. Chilosi M, Facchettti F, Dei Tos AP, Lestani M, Morassi ML, Martignoni G, Sorio C, Benedetti A, Morelli L, Doglioni C, Barberis M, Menestrina F, Viale, G: bcl-2 expression in pleural and extrapleural solitary fibrous tumours. J Pathol 181: 362-367, 1997. 10. Ciappetta P, D’Urso PI, Cimmino A, Ingravallo G, Rossi R, Colamaria A, D’Urso OF: Intramedullary solitary fibrous tumor of dorsal spinal cord. Neuropathology 30:273-278, 2010. 11. Fargen KM, Opalach KJ, Wakefield D, Jacob RP, Yachnis AT, Lister JR: The central nervous system solitary fibrous tumor: a review of clinical, imaging and pathologic findings among all reported cases from 1996 to 2010. Clin Neurol Neurosurg 113:703-710, 2011.
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12. Ferretti GR, Chiles C, Choplin RH, Coulomb M: Localized benign fibrous tumors of the pleura. AJR Am J Roentgenol 169:683-686, 1997. 13. Gessi M, Gielen GH, Roeder-Geyer ED, Sommer C, Vieth M, Braun V, Kuchelmeister K, Pietsch T: Extracranial metastasizing solitary fibrous tumors (SFT) of meninges: histopathological features of a case with long-term follow-up. Neuropathology 33:68-74, 2013. 14. Hanau CA, Miettinen M: Solitary fibrous tumor: histological and immunohistochemical spectrum of benign and malignant variants presenting at different sites. Hum Pathol 26:440-449, 1995. 15. Hasegawa T, Matsuno Y, Shimoda T, Hasegawa F, Sano T, Hirohashi S: Extrathoracic solitary fibrous tumors: their histological variability and potentially aggressive behavior. Hum Pathol 30: 1464-1473, 1999. 16. Hayashi Y, Uchiyama N, Hayashi Y, Nakada M, Iwato M, Kita D, Higashi R, Hirota Y, Kai Y, Kuratsu J, Hamada J: A reevaluation of the primary diagnosis of hemangiopericytoma and the clinical importance of differential diagnosis from solitary fibrous tumor of the central nervous system. Clin Neurol Neurosurg 111:34-38, 2009. 17. Ishii K, Nakamura M, Matsumoto M, Mukai M, Toyama Y, Chiba K: Intramedullary solitary fibrous tumor of the spinal cord. J Orthop Sci 14: 450-454, 2009. 18. Jallo GI, Roonprapunt C, Kothbauer K, Freed D, Allen J, Epstein F: Spinal solitary fibrous tumors: a series of four patients: case report. Neurosurgery 57:E195; discussion E195, 2005. 19. Johnson MD, Powell SZ, Boyer PJ, Weil RJ, Moots PL: Dural lesions mimicking meningiomas. Hum Pathol 33:1211-1226, 2002. 20. Kanahara T, Hirokawa M, Shimizu M, Terayama K, Nakamura E, Hino Y, Mikawa Y, Manabe T: Solitary fibrous tumor of the spinal cord. Report of a case with scrape cytology. Acta Cytol 43:425-428, 1999. 21. Kawamura M, Izawa K, Hosono N, Hirano H: Solitary fibrous tumor of the spinal cord: case report and review of the literature. Neurosurgery 55:433, 2004. 22. Kim TA, Brunberg JA, Pearson JP, Ross DA: Solitary fibrous tumor of the paranasal sinuses: CT and MR appearance. AJNR Am J Neuroradiol 17:1767-1772, 1996. 23. Klemperer P, Rabin CB: Primary neoplasms of the pleura: a report of five cases. Arch Pathol Lab Med 11:385-412, 1931. 24. Kottke-Marchant K, Hart WR, Broughan T: Localized fibrous tumor (localized fibrous mesothelioma) of the liver. Cancer 64:1096-1102, 1989. 25. Louis DN, Ohgaki H, Wiestler OD, Cavenee WK, Burger PC, Jouvet A, Scheithauer BW, Kleihues P: The 2007 WHO classification of tumours of the central nervous system. Acta Neuropathol 114: 97-109, 2007. 26. Malek AM, Weller SJ, Price DL Jr, Madsen JR: Solitary fibrous tumor presenting as a
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symptomatic intraspinal mass: case report. Neurosurgery 40:844-847; discussion 847, 1997. 27. Mariniello G, Napoli M, Russo C, Briganti F, Giamundo A, Maiuri F, Del Basso De Caro ML: MRI features of spinal solitary fibrous tumors. A report of two cases and literature review. Neuroradiol J 25:610-616, 2012. 28. Metellus P, Bouvier C, Guyotat J, Fuentes S, Jouvet A, Vasiljevic A, Giorgi R, Dufour H, Grisoli F, Figarella-Branger D: Solitary fibrous tumors of the central nervous system: clinicopathological and therapeutic considerations of 18 cases. Neurosurgery 60:715-722; discussion 722, 2007. 29. Mordani JP, Haq IU, Singh J: Solitary fibrous tumour of the spinal cord. Neuroradiology 42: 679-681, 2000. 30. Munoz E, Prat A, Adamo B, Peralta S, Ramon y Cajal S, Valverde C: A rare case of malignant solitary fibrous tumor of the spinal cord. Spine 33: E397-E399, 2008. 31. Nagano A, Ohno T, Nishimoto Y, Oshima K, Shimizu K: Malignant solitary fibrous tumor of the lumbar spinal root mimicking schwannoma: a case report. Spine J 14:e17-e20, 2014. 32. O’Connell JX, Logan PM, Beauchamp CP: Solitary fibrous tumor of the periosteum. Hum Pathol 26: 460-462, 1995. 33. Pizzolitto S, Falconieri G, Demaglio G: Solitary fibrous tumor of the spinal cord: a clinicopathologic study of two cases. Ann Diagn Pathol 8: 268-275, 2004.
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INTRAMEDULLARY SOLITARY FIBROUS TUMOR
34. Robert T, Duc C, San Millan Ruiz D, Morard M: Solitary fibrous tumour with intramedullary component: case report and review of the literature. Neurol Neurochir Pol 48:144-149, 2014. 35. Schweizer L, Koelsche C, Sahm F, Piro RM, Capper D, Reuss DE, Pusch S, Habel A, Meyer J, Gock T, Jones DT, Mawrin C, Schittenhelm J, Becker A, Heim S, Simon M, Herold-Mende C, Mechtersheimer G, Paulus W, Konig R, Wiestler OD, Pfister SM, Deimling A von: Meningeal hemangiopericytoma and solitary fibrous tumors carry the NAB2-STAT6 fusion and can be diagnosed by nuclear expression of STAT6 protein. Acta Neuropathol 125:651-658, 2013. 36. Shirzadi A, Drazin D, Gates M, Shirzadi N, Bannykh S, Fan X, Hunt L, Baron EM, King WA, Kim TT, Johnson JP: Surgical management of primary spinal hemangiopericytomas: an institutional case series and review of the literature. Eur Spine J 22:S450-S459, 2013. 37. Tateishi U, Nishihara H, Morikawa T, Miyasaka K: Solitary fibrous tumor of the pleura: MR appearance and enhancement pattern. J Comput Assist Tomogr 26:174-179, 2002. 38. Tihan T, Viglione M, Rosenblum MK, Olivi A, Burger PC: Solitary fibrous tumors in the central nervous system. A clinicopathologic review of 18 cases and comparison to meningeal hemangiopericytomas. Arch Pathol Lab Med 127:432-439, 2003. 39. Vallat-Decouvelaere AV, Dry SM, Fletcher CD: Atypical and malignant solitary fibrous tumors in extrathoracic locations: evidence of their comparability
to intra-thoracic tumors. Am J Surg Pathol 22: 1501-1511, 1998. 40. Vorster SJ, Prayson RA, Lee JH: Solitary fibrous tumor of the thoracic spine. Case report and review of the literature. J Neurosurg 92 (2 Suppl): 217-220, 2000. 41. Wang H, Chen P, Zhao W, Shi L, Gu X, Xu Q: Clinicopathological findings in a case series of abdominopelvic solitary fibrous tumors. Oncol Lett 7:1067-1072, 2014. 42. Westra WH, Gerald WL, Rosai J: Solitary fibrous tumor. Consistent CD34 immunoreactivity and occurrence in the orbit. Am J Surg Pathol 18 (10): 992-998, 1994. 43. Witkin GB, Rosai J: Solitary fibrous tumor of the upper respiratory tract. A report of six cases. Am J Surg Pathol 15:842-848, 1991.
Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Received 23 January 2015; accepted 26 February 2015 Citation: World Neurosurg. (2015) 84, 1:189.e7-189.e12. http://dx.doi.org/10.1016/j.wneu.2015.02.036 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2015 Elsevier Inc. All rights reserved.
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