solitary fibrous tumor ( sft ) is a rare neoplasm that was initially described in the visceral pleura and subsequently reported in extrapleural sites including the pericardium , peritoneum , mediastinum , lung , upper respiratory tract , thyroid , liver , testicle , nasal cavity , parotid , orbit , and meninges .
sft development in the spine is an exceedingly rare event about which little is known .
we present a unique case of an intradural extramedullary malignant sft having an extradural component with pulmonary metastases . to the best of our knowledge ,
this is the second case of malignant sft spine with distant metastases reported in literature .
a 35-year - old female , with no comorbidities , presented with a 1 year history of progressive backache that was followed by lower extremity weakness for 4 months .
neurological examination revealed paraparesis , hypertonia , increased deep tendon reflexes in the lower limbs , positive babinski sign , sustained bilateral ankle clonus and a sensory level of d12 with impaired temperature and proprioceptive sensation .
contrast - enhanced magnetic resonance imaging ( mri ) of thoracolumbar spine revealed an intradural extramedullary mass ( 1.2 cm  1.25 cm ; which was predominantly hyperintense on t2 and hypointense on t1 images ) compressing and displacing cord at d10d11 level toward right side with extradural component ( 9.2 cm  5.2 cm ) extending into left neural foramen with widening at d10d11 level .
contrast - enhanced computed tomography showed large well defined heterogeneously enhancing mass ( 9 cm  8.2 cm  6 cm ) in left paravertebral region extending from d10 to d12 vertebrae .
the mass was seen passing through d10d12 neural foramina and causing its widening and extending into spinal canal causing rightward displacement of spinal cord [ figure 1c and d ] .
she underwent d10d11 laminectomy with excision of intraspinal component of tumor by neurosurgeon from outside . histopathology examination ( hpe )
the tumor cells were positive for cd34 ( diffuse ) , cd99 , ema , bcl2 and negative for cd31 , s100 , cd117 , dog1 on immunohistochemistry ( ihc ) [ figure 2c and d ] .
she was then referred to general surgery department of our institute where she was investigated for distant metastases which was negative , and then she underwent thoracotomy and excision of left paravertebral tumor .
because of the incomplete surgical resection of the tumor and the high risk of locoregional and distant recurrence , adjuvant radiotherapy and chemotherapy was considered , but she went lost to follow - up for 5 months . when she turned up , an mri whole spine and positron emission tomography ( pet ) scan was performed for assessment of extent of disease .
mri revealed a residual mass at the level of d11d12 neural foramina on left side ( 1.5 cm  1.2 cm  1.5 cm ) [ figure 3a and b ] with mild fluorodeoxyglucose uptake and multiple subcentimetric nodular lesions in bilateral lungs suggestive of metastases on pet scan .
she was administered palliative radiotherapy of 20 gy in five fractions over 1 week to the primary residual site and planned for palliative chemotherapy with ifosfamide ( 1.4 g / m ; day 14 ) and epirubicin ( 60 mg / m ; day 12 ) .
( a ) sagittal view and ( b ) axial view of t2 weighted magnetic resonance imaging spine showing intradural extramedullary mass with extradural component .
( c ) axial view and ( d ) coronal view of contrast enhanced computed tomography scan showing left paravertebral mass ( a ) tumor is cellular and in diffuse growth pattern ( h and e , 100 ) .
( b ) tumor cells are round to oval with finely granular chromatin , indistinct cytoplasmic boundaries , and showing few mitosis ( h and e , 400 ) .
( d ) ki-67 proliferation index is ~5 - 7% ( a ) axial view and ( b ) sagittal view of t2 weighted magnetic resonance imaging of spine showing residual tumor
sfts most often affect the pleura , but examples are increasingly being reported at other sites .
spinal sfts are usually intramedullary ( 58% ) or intradural and extramedullary ( 24% ) .
the majority of symptoms with which patients were presenting at time of admission were pain , hypoesthesia , paresis , urinary dysfunction , or a combination of these .
similarly , as in our case , the symptoms consisted of a backache , paraparesis , and loss of sensation in lower extremities .
56% of sft patients are male , and most commonly it is seen on patients between 40 and 60 years old .
two - thirds of sfts on mri were isointense on t1-weighted imaging with the remainder being either heterogeneous or hypointense . nearly , two - thirds of cases were hypointense on t2-weighted imaging with hyperintense being the next most common ( 17% ) . over three - quarters of cases demonstrated diffuse or homogeneous contrast enhancement with gadolinium administration ( 78% ) ; however , a significant portion demonstrated only partial or heterogeneous enhancement ( 21% ) .
. typically , hpe features of sfts are spindle cells embedded in a fibrous matrix in a patternless architecture and alternating hypercellular and hypocellular areas with perivascular hyalinization or myxoid degeneration .
overlapping histologic features , differentiation of sft from other soft tissue tumors may be difficult .
typically , sfts are positive for cd34 , bcl-2 , and cd99 and negative for sma , desmin , pan - cytokeratin , and s-100 protein on ihc .
findings such as nuclear atypia , increased cellularity , necrosis , and > 4 mitoses/10 hpfs , are suggestive of the malignant potential of sfts . in the current case ,
based on previous case reports , malignant sft showed rapid local recurrence and distant metastasis . at present , due to the rarity of the disease , standard therapies for malignant sft have not been well established .
recurrence occurred commonly in cases involving incomplete excision , possibly caused by the level of difficulty in achieving complete resection . in these cases ,
. showed that conventional chemotherapy with anthracycline and ifosfamide is effective in controlling or stabilizing locally advanced and metastatic sfts .
our patient being in metastatic setting , received palliative radiotherapy at local site and was considered for palliative chemotherapy with ifosfamide and epirubicin .
the authors report here the second case of malignant sft of spine with distant metastases .
although malignant sft is extremely rare , it should be considered in the differential diagnosis of spindle cell tumors in the spine .
 solitary fibrous tumor ( sft ) usually originates from the pleura because of abnormal proliferation of fibroblast cells . 
 it is extremely rare for the tumor to originate from the spine . here , 
 we report the second case of malignant sft of thoracic spine with distant metastases in a 35-years - old female . 
Introduction
Case Report
Discussion
Conclusion
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