Solitary fibrous tumor of the spinal cord: A clinicopathologic study of two cases

Recurrent Solitary Fibrous Tumor in Intradural Extramedullary Space: Case Report and Review of the Literature

Solitary fibrous tumor/hemangiopericytoma (SFT/HPC) is a rare neoplasm arising from spindle cells and most commonly arising from pleura. Spinal SFT/HPC is a rare entity; hence, it is not on the top of the differential diagnosis list when a clinician faces a spinal lesion. In the review of the literature, there exist less than 50 case reports of intradural extramedullary SFT/HPC. Here, we present a 54-year-old female patient who underwent subtotal surgical excision of an intradural extramedullary spinal mass pathologically reported to be SFT/HPC and had symptomatic recurrence in the 3^rd year of follow-up. Surgical intervention was unachievable and the patient was given 45 Gy to the surgical cavity followed by a 5.4 Gy boost to visible tumor with external radiotherapy. Patient reported significant relief of her symptoms. We aim to contribute to the formation of a treatment algorithm for this rare entity.

Intradural Extramedullary Solitary Fibrous Tumor of the Thoracic Spinal Cord

Solitary fibrous tumors (SFTs) are rare soft tissue neoplasms that can impact the central nervous system (CNS). SFTs comprise <1% of all primary CNS tumors. Here, we describe a rare case of intradural, extramedullary SFT arising within the thoracic spine that was treated with surgical resection. Histological features were evaluated and revealed a highly cellular tumor with positive expression of BCL2, CD34, CD99, and STAT6 proteins that are consistent with a diagnosis of SFT. We discuss the use of surgical intervention for long-term disease control of spinal SFT and evaluate the role of postoperative radiation therapy in management strategies. Lastly, we review the literature reports of intradural, extramedullary SFTs in the thoracic spine. The importance of molecular characterization by histopathology to properly determine diagnosis and prognosis is emphasized.

Cervical, Intradural Extramedullary Solitary Fibrous Tumor of the Spinal Cord: A Case Report and Review of the Literature

Solitary fibrous tumors (SFTs) are rare, spindle cell neoplasms of the mesenchymal origin. Lesions localized to the spine are exceptionally uncommon, only described in the literature in case reports and small case series. While these lesions are typically benign, there are a few reports in which they recur or present as malignancies. The patient presented in the case herein was a 72-year-old male, who presented with a 1-year history of lower extremity weakness, pain, and numbness and was found to have a cervical, intradural extramedullary tumor. In addition to the case report, the authors perform a thorough review of all previously published cases of spinal SFT.

Spinal Intramedullary Solitary Fibrous Tumor: A Rare and Challenging Diagnosis

Background

Solitary fibrous tumor (SFT) is a benign neoplasm arising in the soft tissue, which can occur anywhere in the body, while it is predominantly found in the visceral pleura. Spinal SFT is quite uncommon, with limited cases having been reported in the literature; especially, SFT occurring in the intramedullary site is extremely rare.

Case presentation

We present a case of a 35-year-old woman presenting with progressive numbness and weakness in the legs and urinary incontinence. Magnetic resonance imaging (MRI) showed an intramedullary lesion with bright enhancement. A diagnosis of spinal hemangioblastoma was suspected, and thus a three-dimensional computed tomographic angiography reconstruction was requested, which also demonstrated an angiomatous lesion. The tumor was completely resected under neurophysiological monitoring. However, histopathological and immunohistochemical examinations revealed an SFT. No adjuvant radiotherapy or chemotherapy was scheduled. The symptoms were relieved completely, and no recurrence or progression was noted during the follow-up.

Conclusion

Though SFT has been considered similar to malignant hemangiopericytoma and the histological classification has always been controversial, the intramedullary location and benign behavior in the present case add to the current understandings of this extremely rare entity.

Solitary Fibrous Tumor/Hemangiopericytoma of Spinal Cord: A Retrospective Single-Center Study of 16 Cases

OBJECTIVE

In this study, we retrospectively reviewed our experience in the surgical management of solitary fibrous tumor (SFT)/hemangiopericytomas (HPCs) of the spinal cord.

METHODS

Sixteen patients with SFT/HPCs of the spinal cord were enrolled in this study. Data on clinical presentation, radiologic findings, histopathologic features, surgical treatment, adjuvant therapy, and prognosis were retrospectively reviewed. Kaplan-Meier curves and log-rank tests were used to identify the prognostic factors for recurrence and overall survival (OS).

RESULTS

Our series included 6 men and 10 women, with a male/female ratio of 1:1.7. Magnetic resonance imaging (MRI) showed slightly hyperintense lesions on T2-weighted images for all 16 patients. All tumors showed positive immunohistochemical staining for signal transducer and activator of transcription 6. Statistical analysis of clinical data showed that age, gender, tumor location, tumor size, medullary compartment location, and Ki-67 index were not associated with recurrence and OS (P > 0.05). However, World Health Organization grade III was significantly associated with recurrence (P < 0.01). Gross total resection (GTR) and postoperative radiotherapy significantly reduced recurrence (P < 0.01 and P < 0.05), but only GTR showed remarkable benefits to improve OS (P < 0.05).

CONCLUSIONS

SFT/HPCs of spinal cord are rare neoplasms with a propensity to recur. Hyperintensity on T2-weighted magnetic resonance imaging combined with positive immunohistochemical staining for signal transducer and activator of transcription 6 are important clues for classification and differentiation of these tumors. The extent of resection, World Health Organization grade, and postoperative radiotherapy might be predictive factors for recurrence. Complete tumor resection should be sought whenever possible, and adjuvant radiotherapy is recommended after surgical resection. Moreover, regular and long-term follow-up is mandatory to monitor recurrence.

Solitary fibrous tumors of the spine: a pediatric case report with a comprehensive review of the literature

Solitary fibrous tumors of the spine are rare lesions. Their description in the literature is limited to case reports and small case series. While generally benign lesions, they can recur and occasionally occur as malignancies. Here the authors present the case of a 10-year-old boy, the youngest patient and first preadolescent reported thus far, with this condition. In addition, they perform a comprehensive review of all previously published cases of spinal solitary fibrous tumors.

Hemorrhagic intramedullary solitary fibrous tumor of the conus medullaris: case report

The differential diagnosis of spinal tumors is guided by anatomical location and imaging characteristics. Diagnosis of rare tumors is made challenging by abnormal features. The authors present the case of a 47-year-old woman who presented with progressive subacute right lower-extremity weakness and numbness of the right thigh. Physical examination further revealed an extensor response to plantar reflex on the right and hyporeflexia of the right Achilles and patellar reflexes. Magnetic resonance imaging of the lumbar spine demonstrated an 8-mm intramedullary exophytic nodule protruding into a hematoma within the conus medullaris. Spinal angiography was performed to rule out an arteriovenous malformation, and resection with hematoma evacuation was completed. Pathological examination of the resected mass demonstrated a spindle cell neoplasm with dense bundles of collagen. Special immunostaining was performed and a diagnosis of solitary fibrous tumor (SFT) was made. SFTs are mesenchymally derived pleural neoplasms, which rarely present at other locations of the body, but have been increasingly described to occur as primary neoplasms of the spine and CNS. The authors believe that this case is unique in its rare location at the level of the conus, and also that this is the first report of a hemorrhagic SFT in the spine. Therefore, with this report the authors add to the literature the fact that this variant of an increasingly understood but heterogeneous tumor can occur, and therefore should be considered in the differential of clinically similar tumors.

MRI Features of Spinal Solitary Fibrous Tumors

Spinal solitary fibrous tumors (SFT) are very rare neoplasms occurring in the spinal canal, with only 38 cases reported in ten years since the first description. We describe two cases of SFT of the spine and review 33 well-documented cases in the literature to define distinctive radiological and surgical features raising the suspicion of a spinal SFT before histological verification. A 67-year-old man with cervical myeloradiculopathy had a large extramedullary tumor of the cervical spinal canal extending from C4 to C7. On MRI the tumor was isointense on T1-sequences and hypointense on T2-sequences, and had marked contrast enhancement. At surgery, the tumor was intradural extramedullary, with no dural or root attachment, but it was adherent to the cord. Complete tumor removal was achieved with good outcome. A 75-year-old man with progressive thoracic myelopathy had an intramedullary tumor at C6 and C7 level, which was hypointense on T1- and T2-weighted images of MRI. At surgery, the tumor was intramedullary and strongly adherent to the cord; it was successfully removed. Both tumors were composed of elongated cells with a collagen-matrix background. Immunohistochemical staining was positive for vimentin, CD34, and bcl-2, and negative for EMA and S-100 protein. A careful analysis of our own and the other reported cases of spinal SFTs may disclose some peculiar features of this rare tumor. A spinal intramedullary or extramedullary tumor, hypointense on T2-weighted images of MRI, which intraoperatively shows hard consistency, scarce vascularization, no nerve root involvement, no or weak dural attachment, absence of arachnoidal interface, and adherence to the spinal cord may suggest the diagnosis of SFT.

Solitary fibrous tumor of the central nervous system: a 15-year literature survey of 220 cases (August 1996-July 2011)

We reviewed the world literature on solitary fibrous tumors of the central nervous system from August 1996 to July 2011, focusing on both clinicopathological features and diagnostic findings. The anatomical distribution of the 220 cases reported so far reveals that most are intracranial and just over one-fifth are intraspinal. In decreasing frequency, intracranial tumors involve the supratentorial and infratentorial compartments, the pontocerebellar angle, the sellar and parasellar regions, and the cranial nerves. Intraspinal tumors are mainly located in the thoracic and cervical segments. Although most solitary fibrous tumors of the central nervous system are dural based, a small subset presents as subpial, intraparenchymal, intraventricular, or as tumors involving the nerve rootlets with no dural connection. Preoperative imaging and intraoperative findings suggest meningioma, schwannoma or neurofibroma, hemangiopericytoma, or pituitary tumors. Immunohistochemistry is critical to establish a definitive histopathological diagnosis. Vimentin, CD34, BCL2, and CD99 are the most consistently positive markers. The usual histologic type generally behaves in a benign manner if complete removal is achieved. Recurrence is anticipated when resection is subtotal or when the tumor exhibits atypical histology. The proliferative index as assessed by MIB1 labeling is of prognostic significance. Occasionally, tumors featuring conventional morphology may recur, perhaps because of minimal residual disease left behind during surgical extirpation. Rare extracranial metastases and tumor-related deaths are on record. Surgery is the treatment of choice. Stereotactic and external beam radiation therapy may be indicated for postsurgical tumor remnants and for unresectable recurrences. Long-term active surveillance of the patients is mandatory.

Solitary Fibrous Tumor of the Central Nervous System

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.

The central nervous system solitary fibrous tumor: a review of clinical, imaging and pathologic findings among all reported cases from 1996 to 2010

OBJECTIVE

Central nervous system (CNS) solitary fibrous tumor (SFT) is a rare lesion first identified as a unique entity in 1996. We describe two cases treated at the University of Florida followed by a review of all reported cases of CNS SFT between 1996 and 2010.

METHODS

A review of the literature was performed to identify all reported cases of CNS SFT.

RESULTS

189 cases (including the two presented herein) were discovered, of which 46 were spinal and 143 were intracranial. Demographic, imaging, and pathologic findings are presented. Roughly 6% of reported lesions are malignant. Subtotal resection (STR) was associated with a 16-fold increased odds of recurrence (OR 15.9, 95% CI 5.5-46.1), although mean follow-up was shorter in those cases of GTR without recurrence.

CONCLUSION

CNS SFT is a rare lesion. Six percent of lesions are malignant. GTR is superior to STR although the degree of superiority is not clear.

Solitary fibrous tumour of the central nervous system: pathological study of eight cases and review of the literature

AIMS

Solitary fibrous tumours (SFT) 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 haemangiopericytoma or fibrous meningioma. We present herewith a pathological study of eight patients with SFT and compare our results with the published data.

METHODS

All tumours diagnosed as SFT over a period of 15 years were retrieved from the files of La Rabta Hospital Department of Pathology, Tunisia. Routine histological sections were prepared from formalin-fixed, paraffin-embedded specimens. Immunohistochemical analysis was performed using antibodies raised against vimentin, CD34, CD99, Bcl-2 and MIB-1.

RESULTS

The SFT group consisted of four males and four females with a mean age of 44 years. The tumours were supratentorial in six cases, tentorial in one case and located in the lateral right ventricle in the last case. All patients underwent surgery as initial treatment. Histologically, SFT were similar to their soft tissue counterparts. Two cases demonstrated increased cellularity, marked nuclear hyperchromasia and marked cellular pleomorphism. Only the later two cases recurred after 6 months of follow-up.

CONCLUSION

Little is known about the biological behaviour of SFT, although most seem amenable to total resection.

Solitary fibrous tumor in the cervical spine with destructive vertebral involvement: a case report and review of the literature

INTRODUCTION

Recently, solitary fibrous tumors occurring in spine-related lesions have been reported. However, the destruction of vertebral bodies by this type of tumor has not been reported.

MATERIALS AND METHODS

A 71-year-old female presented with pain from a mass on the right side of her neck. Plain radiographs of the cervical spine showed collapse of the C5 vertebral body and dislocation of the C4 vertebral body. The MRI image showed a large mass surrounding C4 and C5, which had low signal intensity in the T1W image and high signal intensity in the T2W image. At first, resection of the tumor and spinal fusion was performed by anterior approach.

RESULTS

Histology revealed a solitary fibrous tumor with proliferating spindle cells. Immunohistochemistry showed positive stains for vimentin and CD34. One year postoperatively, a local recurrence manifested extensive destruction of the C4 and C5 vertebral bodies. Then, palliative surgery with posterior cervical instrumentation and radiation therapy were performed. Because the destruction proceeded and the rods were broken 2 years after, she underwent additional occipito-cervical instrumentation.

CONCLUSIONS

This is the first report of a solitary fibrous tumor that involves the destruction of the spinal structure. An extensive destruction of the vertebral body by the solitary fibrous tumor needs to be aware in treating this tumor with spinal involvement.

Solitary fibrous tumour of thyroid: report of two cases with immunohistochemical features and literature review

Solitary fibrous tumour (SFT) is a rare tumour principally found in adults in the pleural cavity. Extrapleural occurrences are rare. Two cases of SFT of the thyroid gland are described in this paper showing their distinctive microscopical architecture, namely "patternless growth pattern". It is characterized by a bland spindle-cell proliferation alternating hyper- and hypo-cellular areas, keloid-like hyalinization and a focal hemangiopericytoma-like vascular pattern. Tumour cells revealed a diffuse strong positivity for CD34, CD99, bcl-2 and Vimentin, but negativity for Desmin, EMA, AE1/AE3, SMA, S-100 and CD31 antibodies. The differential diagnosis of thyroid SFT includes different types of spindle cell proliferation, benign and malignant mesenchymal tumours, medullary thyroid carcinoma, fasciitis-like papillary carcinoma, and undifferentiated (anaplastic) carcinoma. However, the morphologic and immunohistochemical findings of SFT are so characteristic that this diagnosis seldom represent a difficulty.

A dumbbell-shaped solitary fibrous tumor of the cervical spinal cord

A 40-year-old Asian female presented with a 2-month history of right shoulder pain and right triceps weakness. MRI revealed an extramedullary, extradural, dumbbell-shaped spinal cord tumor with C6 to C7 iso- and hyperintensity on T1 and T2 weighted imaging, respectively. Histological examination revealed monomorphous spindle cells with a storiform pattern. Immunohistochemistry was positive for CD34, CD99, and negative for EMA, SMA, and S100; solitary fibrous tumor (SFT) was confirmed.

A solitary fibrous tumor in the broad ligament of the uterus

Solitary fibrous tumor (SFT) is a rare mesenchymal tumor that occurs preferentially in the pleura. Although it has been described at some extrathoracic sites, its occurrence in the female genital tract is extremely rare. We are the first to report on an unusual case of a large (14cm in the largest diameter) SFT localized in the broad ligament of the uterus in a 50-year-old woman. The patient underwent surgical tumor extirpation and has remained well without any sign of local tumor recurrence after 6 years of follow-up. We discuss the clinical aspects, the gross macroscopic appearance, the histologic findings, and the differential diagnosis, and provide a review of the literature.

Solitary Fibrous Tumor Arising from Cranial Nerve VI in the Prepontine Cistern: Case Report and Review of a Tumor Subpopulation Mimicking Schwannoma

OBJECTIVE:

The authors present a report of a solitary fibrous tumor (SFT) arising from the intradural component of the VIth cranial nerve as it travels through the prepontine cistern. SFTs of the central nervous system are extremely rare entities that clinically masquerade as dural-based lesions, such as meningiomas or hemangiopericytomas. Because of their infrequency and clinical similarity to other central nervous system (CNS) lesions, diagnosis is largely dependent on pathological features. In this study, the authors define a subpopulation of SFTs that seem to arise directly from nerve, rather than meninges, and clinically mimic the appearance of a schwannoma.

CLINICAL PRESENTATION:

The patient was a 29-year-old woman with a several-month history of progressive right arm and leg numbness and mild hemiparesis, with the development of diplopia 2 weeks before admission. Outside imaging revealed a 3.9-cm mass in the prepontine cistern with extension into Meckel's cave and the cavernous sinus, resulting in significant brainstem compression.

INTERVENTION:

The patient underwent preoperative angiography with embolization of feeding vessels off of the left meningohypophyseal trunk. The patient was then taken to the operating room by a combined neurosurgical and ear, nose, and throat team, where the patient underwent a retrolabyrinthine/subtemporal craniotomy for tumor resection. During resection of the prepontine component, the tumor was identified as originating from the left Cranial Nerve VI as it traversed through the prepontine cistern. Resection of the tumor component involving the cavernous sinus and Meckel's cave was deferred for follow-up treatment with intensity-modulated radiation therapy. Pathological examination revealed tissue consistent with the diagnosis of SFT.

CONCLUSION:

SFTs involving the CNS are rare entities that are almost always diagnosed after tissue is obtained because of their clinical and radiographic similarity to meningiomas. This patient had an SFT masquerading as a VIth cranial nerve schwannoma. Although the natural history of SFTs in the CNS is not completely understood, correct diagnosis is important, given the rate of recurrence found in the more common pleural-based SFT and examples of CNS SFTs with malignant features.

MR imaging of solitary fibrous tumors in the head and neck

Objective

Solitary fibrous tumor (SFT) is a very rare tumor. The purpose of this study is to determine the MR imaging features of SFT in the intracranial and extracranial head and neck regions.

Materials and Methods

We retrospectively reviewed six MR images and two CT images of six histologically proven cases of SFT that occurred in four men and two women, and their ages ranged from 46 to 59 years. These imaging findings were correlated with the microscopic findings of their surgical specimens.

Results

Six SFTs arose in the meninges (the petrous ridge and the pituitary fossa), the parotid gland, the parapharyngeal space, the buccal space and the maxillary sinus. On the MR images, SFTs in the intracranial and extracranial head and neck regions were mostly isointense to the muscle on the T1-weighted images, they were hyperintense on the T2-weighted images and they all had intense enhancement. On the T1- and T2-weighted images, hypointense lines were observed within in five SFTs. On the CT images, the SFTs were hypodense to the muscle on the unenhanced images and they were heterogeneously enhanced on the contrast-enhanced images. An exceptional case of pituitary SFT was hypointense on the T2-weighted images and it was hyperdense on the unenhanced CT images, which correlated with the increased collagenous component and the cellular compactness.

Conclusion

The imaging features of SFT are nonspecific; however, SFT should be included in the differential diagnosis of masses involving the intracranial and extracranial head and neck regions.