Solitary fibrous tumours of the meninges: case series and literature review

Intracranial Solitary Fibrous Tumor of the Skull Base: 2 Cases and Systematic Review of the Literature

BACKGROUND

Intracranial solitary fibrous tumors (ISFTs) are rare neoplasms of mesenchymal origin that originate from the meninges. ISFTs of the skull base can be challenging to treat, as resection can be complicated by skull base anatomy. We present 2 cases of ISFT, the first manifesting with compressive cranial neuropathy from Meckel cave involvement and the second a posterior fossa lesion causing symptomatic hydrocephalus.

METHODS

A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PubMed database was queried with title/abstract keywords "intracranial," "solitary fibrous tumor," "hemangiopericytoma," "SFT," and "HPC." Search results were reviewed to exclude cases not involving the skull base. References from all selected articles were reviewed for potential additional cases. Patient demographic and clinical data from 58 identified skull base cases were collected for qualitative synthesis.

RESULTS

Visual disturbances were the most common presenting symptom (30 cases, 52%) followed by headache (22 cases, 38%). The most common site of involvement was the sellar/parasellar region (18 cases, 31%) followed by middle fossa/temporal bone (14 cases, 24%). Resection was performed in 55 cases; gross total resection was reported in 26 cases (45%) and subtotal resection was reported in 21 cases (36%). Tumor recurrence was documented in 15 cases (26%) with median and mean follow-up periods of 16 and 29.9 months, respectively.

CONCLUSIONS

We discuss presentation, imaging, histopathology, and management considerations for ISFTs while highlighting the potentially complex nature of skull base lesions and need for multidisciplinary approach to treatment.

A review of solitary fibrous tumor/hemangiopericytoma tumor and a comparison of risk factors for recurrence, metastases, and death among patients with spinal and intracranial tumors

Meningeal solitary fibrous tumors (SFTs) and hemangiopericytomas (HPCs) had been combined into a single classification until 2016. Recurrence and metastases rates are still understudied, especially for spinal SFT/HPCs. Here, we describe CNS SFT/HPCs and predictors for recurrence, metastases, and death, in spinal and intracranial SFT/HPCs, separately. We collected data from studies with patient-level data available on primary SFT/HPCs from multiple online databases. Clinico-demographic data, surgical outcomes, recurrence, metastases, and death rates were abstracted. We used logistic and Cox regression models to identify predictors for recurrence, metastases, and death for spinal and intracranial SFT/HPCs. Twenty-nine studies (368 patients) were included. Higher histological grade and subtotal resection were associated with recurrence (p values < 0.05), while higher histological grade and recurrence (p values < 0.005) were associated with metastases formation. Time to recurrence (p < 0.005) and metastases (p < 0.001) formation were shorter for spinal SFT/HPCs. Death rates were higher among intracranial SFT/HPC patients (p value = 0.001). Among patients with higher histological grade, rates of metastases formation were different between intracranial and spinal SFT/HPCs. Risk of metastases was higher in the first 5 years from surgery for both intracranial and spinal SFT/HPCs. Meningeal SFT/HPCs patients have high rates of recurrence and metastasis, which occur mostly within the first 5 years after diagnosis. Spinal and intracranial SFT/HPCs show similar behavior, but spinal SFT/HPCs tend to develop metastases and recurrences in a shorter interval of time. Careful follow-up for spinal SFT/HPCs should be considered because spinal cases seem to be slightly more aggressive and require more attention.

Rare Occurrence of an Intraocular Choroidal Solitary Fibrous Tumor/Hemangiopericytoma

Purpose

Tumors previously diagnosed as solitary fibrous tumors (SFT) and hemangiopericytomas (HPC) are characterized by the NAB2-STAT6 fusion gene, leading to nuclear STAT6 expression, and are now considered part of one SFT/HPC tumor entity by the 2016 World Health Organization Classification of Tumors of the Central Nervous System. We present the first primary choroidal SFT/HPC with the diagnosis confirmed by STAT6 expression.

Procedures

A 51-year-old man underwent enucleation for a choroidal mass, which revealed a spindle cell neoplasm involving the optic nerve, without extrascleral extension. Immunohistochemical stains for S-100, melan-A, tyrosinase, and HMB45 were all negative; however, detection of monosomy 3 by FISH favored a choroidal spindle cell melanoma. Four years later, he presented with hepatic metastases of a spindle cell tumor, and a year later with an epithelioid malignancy involving the calvarium.

Results

The calvarial tumor showed nuclear STAT6 immunoreactivity, supporting the diagnosis of SFT/HPC. Retrospectively, the choroidal and hepatic masses were also found to demonstrate nuclear STAT6 expression, supporting the diagnosis of a primary choroidal SFT/HPC with metachronous metastases to the liver and calvarium.

Conclusions

This case highlights the significance of considering SFT/HPC in the diagnosis of intraocular spindle cell tumors and the importance of STAT6 immunohistochemistry in the evaluation of such tumors.

Solitary fibrous tumor of central nervous system masquerading as meninigioma: Report of a rare case

INTRODUCTION

Solitary fibrous tumor (SFT) is a rare neoplasm of mesenchymal origin that occurs most often in the visceral pleura. It rarely occurs in the central nervous system (CNS). If they occur intracranially, they are extra-axially located and develop from the meninges.

CASE REPORT

Herein, we present a case of SFT in a 45 years old female. MR imaging showed isointense to hypointense signal intensity, and marked enhancement. Microscopically, the tumors showed characteristic "patternless-pattern" architecture. Elongated tumor cells formed fascicles alternating with hypocellular densely collagenous stroma. Immunohistochemistry for STAT6, CD34, BCL2 and CD99 favours the definitive diagnosis of SFT.

CONCLUSION

In general, complete surgical resection may offer the best chance of a favourable clinical outcome. Their biological features remain largely unknown. Hence, the clinical management and prognosis is often challenging due to the lack of comprehensive data.

MR imaging of intracranial solitary fibrous tumor: a retrospective study of 7 cases

OBJECTIVE

To investigate the MR imaging diagnostic features of intracranial solitary fibrous tumors (ISFTs).

MATERIALS AND METHODS

Seven patients (mean age of 52.9 years; M:F=3:4) with histopathologically proven ISFTs were identified at our institute. Clinical presentations and pathological features were reviewed. MR Imaging findings including signal intensity, gadopentetate dimeglumine enhanced pattern, and diffusion-weighted imaging (DWI) characterization of the tumors were retrospectively evaluated.

RESULTS

Six tumors showed a multi-lobular contour. Five tumors showed heterogeneous signal intensity, and two tumors showed homogeneous signal intensity on T1WI. Low signal intensity linear, curved or interlacing lines were observed within the tumors in all seven cases. Seven tumors demonstrated moderate or strong enhancement, six showed heterogeneous enhancement, and one homogenous enhancement. All tumors showed heterogeneous signal intensity on DWI.A ring-like high signal intensity band distributed around within the tumor was noted in six cases on DWI.

CONCLUSION

Diagnostic evidence for ISFT on MR image includes heterogeneous signal intensity, intense enhancement of T2 signal intensity, low signal intensity lines within the tumor, heterogeneous signal intensity on DWI and a ring-like band around the tumor on DWI.

Solitary fibrous tumor of the sellar region treated with adjuvant radiation therapy

The solitary fibrous tumor of central nervous system is rare. Herein, a case of solitary fibrous tumor arising from sellar region is described. A 60-year-old man underwent subtotal excision of the tumor because of extensive infiltration of optical and vascular structures. In view of the presence of residual tumor, he was treated with adjuvant radiation therapy. After a follow-up period of 1 year, there was no progression of the lesion evident on magnetic resonance imaging of the brain. Solitary fibrous tumor should be considered as one of the differential diagnosis of a mass lesion arising in sellar region. Immunohistochemistry with CD34 is valuable for discerning the diagnosis. Complete surgery should be the goal of treatment and adjuvant radiation therapy may be considered for residual or recurrent disease.

Rapid recurrence and bilateral lungs, multiple bone metastasis of malignant solitary fibrous tumor of the right occipital lobe: report of a case and review

BACKGROUND

Intracranial malignant solitary fibrous tumor (MSFT) is extremely rare. The authors report a case of MSFT of the right occipital lobe with a rapid recurrence and bilateral lung, multiple bone metastasis.

CASE PRESENTATION

The patient was a 25-year-old male presenting with headache, nausea and visual disturbances without obvious cause. Three times right-side occipital craniotomies were performed and two times postoperative conformal radiotherapy were administered within one year. 4 months after the third time of right-side occipital craniotomy, the patient felt right chest pain and neck pain. Positron emission tomography/computed tomography (PET/CT) showed tumor recurrence of the right occipital lobe and bilateral lung metastasis, multiple bone metastasis including: vertebrae, libs, the left iliac wing, sacrum, the right ischium and upper parts of both femurs. Ultrasound guided puncture biopsy of left-side back of the neck and CT guided puncture biopsy of the third lumbar vertebra were performed. General sample showed grayish white or grayish red with irregular shape. Histopathologically, the tumor was composed of areas of alternating hypercellularity and hypocellularity with spindle-shaped cells, which arranged as fascicular, storiform pattern or patternless pattern, with intervening irregular eosinophilic collagen bundles. Some areas showed hemangiopericytoma-like perivascular pattern and perivascular hyalinization. Tumor cells were pleomorphic with mitotic counts of more than 4 per 10 high power fields and showed coagulative necrosis. Immunohistochemically, tumor cells were diffusely positive for vimentin and CD99, focal positive for CD34, bcl-2 and Actin. Ki-67 labelling index was more than 40%. The final pathological diagnosis was MSFT of the right occipital lobe, metastatic MSFT of left-side back of the neck and the third lumbar vertebra.

CONCLUSION

The MSFT of the right occipital lobe with recurrence and bilateral lung, multiple bone metastasis is extremely rare. Although intracranial MSFT is extremely rare, it should be considered in the differential diagnosis. Definite diagnosis depended mainly on pathological morphology and immunohistochemistry. The prognosis of MSFT is poor due to recurrence and metastasis. Complete resection of intracranial MSFT is difficult, and carful follow-up is needed.

Intramedullary solitary fibrous tumor of cervicothoracic spinal cord

Solitary fibrous tumor is rare benign mesenchymal neoplasm. The spinal solitary fibrous tumor is extremely rare. The authors experienced a case of intramedullary solitary fibrous tumor of cervicothoracic spinal cord in a 48-year-old man with right lower extremity sensory disturbance. Spinal MRI showed intradural mass lesion in the level of C7-T1, the margin between the spinal cord and tumor was not clear on MRI. A Left unilateral laminectomy and mass removal was performed. Intra operative finding, the tumor boundary was unclear from spinal cord and it had intramedullary and extramedullary portion. After surgery, patient had good recovery and had uneventful prognosis. Follow up spinal MRI showed no recurrence of tumor.

Total resection of a solitary fibrous tumor of the sellar diaphragm: A case report

The present study reports the case of a patient with a vision impairment in the right eye. Head computed tomography revealed a round, hyperdense mass in the sellar and suprasellar regions. Pituitary gland magnetic resonance imaging (MRI) revealed isointensity on T1- and T2-weighted imaging. Tumor-enhanced scanning showed heterogeneous contrast enhancement. The initial diagnosis was that of meningioma or pituitary tumor. A total tumor resection was performed using a right pterional approach under general anesthesia. During surgery, the base of the tumor was located on the sellar diaphragm of the left anterior pituitary stalk. The pathological diagnosis was of a solitary fibrous tumor (SFT). The patient had no post-operative diabetes insipidus or idiopathic pituitary hypofunction. The clinical experience, imaging information and pathological features of SFT in this case report may provide a reference for correct diagnosis and total resection of SFTs in the sella turcica.

Solitary fibrous tumors of the soft tissues: imaging features with histopathologic correlations

Purpose

To describe the imaging features of soft tissue solitary fibrous tumors, with histopathological correlations and clinical outcome.

Material and methods

Twenty-seven patients with histologically proven SFTs were retrospectively evaluated. Imaging studies included six radiographs, five U/S studies, eighteen CT scans, fourteen MRI exams, and one angiography.

Results

On CT scans, two lesions were isodense and five were mildly hypodense compared to muscle while 11 lesions appeared heterogeneous-mixed of iso and hypodense areas. Heterogeneous enhancement was depicted in 13 lesions and four lesions enhanced homogeneously. Six lesions were partially calcified. On T1W MR images, seven lesions were isointense and one was slightly hyperintense relative to adjacent muscles while five lesions appeared heterogeneous-mixed of iso and hypointense areas. T2W images showed high SI in two cases and heterogeneous-mixed in seven cases. Enhancement was heterogeneous in six and homogeneous in four lesions. Patchy unenhanced areas (on CT and T1W MR images) along with patchy areas of low to markedly high SI on T2W images were depicted in 19 lesions. The enhanced portions correlated to areas of increased vascularity and cellularity. The four clinically more aggressive lesions could not be predicted on imaging.

Conclusion

Typical soft tissue SFTs are deep masses made of isodense and isointense areas relative to adjacent muscles mixed with hypodense and hypointense areas on unenhanced CT and MR T1W respectively. Variable enhancement patterns and mixed to high signal intensities on MRT2W are attributed to tumor’s cellularity, vascularity, collagen distribution and/or degeneration. Heterogeneity of SFTs affects imaging features on MRI and CT modalities. The biological behavior of soft tissue SFTs can not be predicted based solely either on histopathologic or imaging evaluation.

"Hitting all the right markers to save a life" Solitary fibrous tumors of the central nervous system: Case series and review of the literature

Background:

Solitary fibrous tumors (SFTs) of the central nervous system are uncommon. Their biological features remain largely unknown; hence, the clinical management and prognosis is often challenging due to the lack of comprehensive data. For this reason, we present two cases of large SFTs to illustrate a comprehensive review.

Methods:

This was a retrospective analysis of two patients: a 65-year-old male with a left parietooccipital lesion and a 70-year-old female with a right parietal convexity mass.

Results:

Gross total resection was performed in the male patient with no recurrence 30 months after resection. The second patient received stereotactic radiosurgery for what was initially thought to be a parafalcine meningioma; however, continued growth 1 year later prompted an open resection, with pathology indicative of an SFT. The tumor recurred the following year requiring repeat resection. Unfortunately, due to the aggressive nature of the lesion, the patient eventually succumbed to tumor burden a year later.

Conclusion:

Based on the literature review, the sometimes observed aggressive growth pattern, and also, the potential for malignant transformation, we recommend complete resection of SFTs with close sequential follow-up.

Treatment of intracranial solitary fibrous tumors with gamma knife radiosurgery: report of two cases and review of literature

BACKGROUND AND IMPORTANCE

Gamma knife radiosurgery (GKRS) as a treatment option has not been described in the management of typical intracranial solitary fibrous tumors.

CLINICAL PRESENTATION

After presenting with visual decline, case A underwent a bioccipital craniotomy during which 90% of tumor was thought to have been resected. She unfortunately required re-resection 56 months later for recurrence when she again presented with progressive visual decline, altered mental status, and headaches. A subtotal resection was performed, because there was extensive tumor involvement of the torcula, straight sinus, and bilateral transverse sinuses. She was subsequently referred for GKRS. Although neurologically intact, with the exception of an upper extremity tremor, case B had undergone 7 surgeries for a posterior fossa tumor over the several decades preceding GKRS. The tumors targeted with GKRS were found on serial MRI scans and were thought to be asymptomatic at the time of treatment. At 7 and 14 months after GKRS, case A experienced tumor shrinkage, which remained stable 20 months after treatment. Effective local tumor control was seen in case B with tumor shrinkage at 3, 8, and 13 months after treatment. However, repeat GKRS was required for case B, because an out-of-field recurrence was found 15 months after the initial GKRS.

CONCLUSION

Based on this report and available information in the literature, radiosurgery appears to be a reasonable approach for patients with recurrent or residual intracranial solitary fibrous tumors.

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.

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.

An intracranial malignant solitary fibrous tumor

Intracranial malignant solitary fibrous tumor (SFT) is very rare. It was identified in a 39-year-old female patient who underwent malignant transformation over 6 months. MRI revealed an 8 × 5 × 6 cm mass with heterogenous strong enhancement in the left occipital lobe. Histologic findings and immunophenotype (positive for CD34, bcl-2 and vimentin, and negative for epithelial membrane antigen or S100 protein) of the primary tumor were typical of SFT. However, there was a focal area (<10% of tumor volume) showing hypercellularity, nuclear pleomorphism and increased Ki-67 labeling index (LI) of 10% (average, 1%). At the second operation, the recurrent tumor revealed full-blown histologic features of malignant SFT, such as infiltrative brain invasion, marked nuclear pleomorphism, frequent mitotic figures (15/10 high power fields), and high Ki-67 LI (25%). The presence of atypical histologic finding or increased Ki-67 LI in the typical SFT, although it is focal, needs to be mentioned in the diagnosis and also may require more aggressive surgical management.

Is sagittal sinus resection in falcine meningiomas a factor of bad surgical outcome?

OBJECTIVE

Meningiomas arising purely from the falx below the longitudinal sinus represents a surgical challenge for the neurosurgeon. The authors discuss the new aspects of surgical details that may avoid complications and determine the prognosis.

MATERIALS AND METHODS

We retrospectively evaluated our surgical experience from June 2004 to January 2010. Seventy patients harboring falcine meningiomas were included and submitted for surgical resection. All historical records, office charts and images were reviewed in order to sample the most important data regarding epidemiology, clinical pictures, radiological findings and surgical results, as well as the main complications. The patients were divided into three main groups: anterior third 32 patients (Group A), middle third 15 patients (Group B), 23 patients in the posterior third of falx (Group C).

RESULTS

In Group A, total macroscopic resection was achieved in 31 out of 32 cases (96.87%). Twenty five patients had Rankin 0, five patients had Rankin 1-2, two patients had Rankin 6. In Group B (15 patients), 10 patients had gross resection and Rankin 0, four patients had Rankin 1-2 and one patient had Rankin 6. In Group C (23 patients), 20 patients were absolutely able, Rankin score 0, after six months postoperative period (83.3% had excellent results) and no mortality. Four cases had Rankin score 1 - 2 (16.6%). Ten cases (43.47%) had Simpson I resection and ten cases (43.47%) had Simpson II.

CONCLUSION

Despite larger lesion volumes, Group A meningiomas had a better outcome due to the position they were in, the tumor and surrounding structures. The preoperative preparation and surgical planning can preserve sagittal sinus; but in some cases, this is not possible. Sagittal sinus resection, as proven by this paper, is still a factor of bad surgical outcome. In the middle and posterior third, resection of sagittal sinus is a factor of a bad outcome, due to cerebral infartion.

Bifrontal solitary fibrous tumor of the meninges

Background:

We report the case of a bifrontal solitary fibrous tumor (SFT) arising from the meninges. The points of interest in this case report are the particular imaging appearance, the immunohistochemical findings and the surgical features.

Case Description:

A 53-year-old Caucasian male presented with a 1-year history of behavioral changes, attention disorders and anterograde memory disorders. Magnetic resonance imaging revealed a bifrontal heterogeneous lesion attached to the anterior falx cerebri with a prominent multicompartmental cystic part. The patient underwent craniotomy for a sub-total resection of the tumor. At surgery, the multicystic component was highly vascularized and encased the anterior cerebral arteries. Neuropathological findings were consistent with a solitary fibrous tumor. Despite the absence of malignant features, there was a focal expression of p53.

Conclusion:

SFT is a pathological entity with specific immunohistochemical features; it has frequently been misdiagnosed in the past. The multicystic imaging appearance of this SFT and the particular p53 immunohistochemical staining are features that should be added to the growing data on intracranial SFTs. The surgical features described (high vascularization and partial vessel encasement) may help improve surgical planning.

Intracranial solitary fibrous tumor: imaging findings

OBJECTIVE

To study the neuroimaging features of intracranial solitary fibrous tumors (ISFTs).

MATERIALS AND METHODS

Retrospective study of neuroimaging features of 9 consecutive histopathologically proven ISFT cases. Location, size, shape, density, signal intensity and gadolinium uptake were studied at CT and MRI. Data collected from diffusion-weighted imaging (DWI) (3 patients), perfusion imaging and MR spectroscopy (2 patients), and DSA (4 patients) were also analyzed.

RESULTS

The tumors most frequently arose from the intracranial meninges (7/9), while the other lesions were intraventricular. Tumor size ranged from 2.5 to 10 cm (mean=6.6 cm). They presented multilobular shape in 6/9 patients. Most ISFTs were heterogeneous (7/9) with areas of low T2 signal intensity that strongly enhanced after gadolinium administration (6/8). Erosion of the skull was present in about half of the cases (4/9). Components with decreased apparent diffusion coefficient were seen in 2/3 ISFTs on DWI. Spectroscopy revealed elevated peaks of choline and myo-inositol. MR perfusion showed features of hyperperfusion.

CONCLUSION

ISFT should be considered in cases of extra-axial, supratentorial, heterogeneous, hypervascular tumor. Areas of low T2 signal intensity that strongly enhance after gadolinium injection are suggestive of this diagnosis. Restricted diffusion and elevated peak of myo-inositol may be additional valuable features.

A primary atypical solitary fibrous tumor of the sella mimicking nonfunctional pituitary adenoma: a case report

We reported a 32-year-old male with a sellar solitary fibrous tumor who presented with headache and affliction in the left eye. Serum biochemical examination revealed hypoglycemia. The tumor was assumed to be a nonfunctional pituitary adenoma preoperatively. A subtotal resection of the tumor was performed. Immunohistochemically, atypical solitary fibrous tumor was established. The residual tumor had no progression or distant metastasis at a 44-month follow-up after gamma-knife stereoradiotherapy.

Meningeal hemangiopericytomas and hemangiopericytoma/solitary fibrous tumors of extracranial soft tissues: a comparison

The current World Health Organization (WHO) classification of central nervous system tumors lists meningeal hemangiopericytomas (HPC) and meningeal solitary fibrous tumors (SFT) as separate entities. On the contrary, SFT and HPC of soft tissues are regarded in the WHO soft tissue fascicle as features of the same entity. The clinical data, histology, and immunohistochemistry of 18 cases of meningeal HPC and 12 cases of peripheral soft tissue HPC-SFT were compared. Both intracranial and soft tissue lesions had significant similarities that included staghorn vasculature, necrotic areas, cytologic atypia, and positivities for CD99, collagen IV, and reticulin. Nevertheless, intracranial tumors were more cellular than HPC-SFT of soft tissues and had fewer collagen bands. Meningeal HPC in addition had more mitoses, higher Ki67 index, stained less intensely for CD34 and B-cell lymphoma 2 (BCL2) than HPC-SFT of soft tissues. Meningeal HPCs recurred in 13 out of 14 cases (92.9%). One of the patients died in the postoperative period for a recurrent lesion 5 years after the diagnosis, and another patient developed an extracranial metastasis 13 years after surgery. None of the six cases of HPC-SFT of soft tissues available for follow-up recurred. Both meningeal and soft tissue tumors appear to represent different features of the same entity. A more aggressive phenotype of the tumor together with incomplete surgical resection of intracranial lesions might explain the noticeable clinical difference between HPC of the meninges and HPC-SFT of soft tissues.

Orbital solitary fibrous tumor : a case report and diagnostic clues

Orbital solitary fibrous tumor (SFT) is a rare tumor originating from the mesenchyme. We describe the clinical presentations, radiological and operative findings, and pathological features of a patient with orbital SFT. The patient was a 46-year-old female who presented with progressive proptosis advanced for 20 months. On ophthalmological examination, no visual impairment was detected, but left eye was found to be obviously protruded on exophthalmometry. Orbital magnetic resonance imaging showed a 2.5 x 2 x 2 cm, intensely enhanced mass in the left orbit, which compressed the eyeball forward and the optic nerve downward. The patient underwent frontal craniotomy with superior orbitotomy and gross total resection was performed for the tumor. The histopathological diagnosis including immunohistochemistry was a SFT. After the surgery, proptosis was markedly relieved without visual impairment. Although orbital SFT is extremely rare, it should be considered in the differential diagnosis of orbital tumors. Clinical presentations such as painless proptosis and CD34 immunoreactivity play a significant role in differentiating orbital SFT from other spindle-cell neoplasms of the orbit.

Solitary fibrous tumour of the ethmoid sinuses and anterior fossa

A 68-year-old woman presented with a 2 month history of progressive headache, left extremity weakness, and cognitive difficulties. Neuroimaging results demonstrated a macrocystic tumour attached to ethmoid sinuses and disclosed atypical findings. The tumour was totally removed. All the symptoms and signs ameliorated after surgery. Histological and immunohistochemical examinations led to a diagnosis of solitary fibrous tumour. A solitary fibrous tumour could be seen in various intracranial areas but ethmoid sinuses and anterior fossa are not an exceptional site. They appear as extra-axial tumours with a characteristic pattern on magnetic resonance imaging (MRI), but the cystic component is very unusual. Intracranial location and MRI features of this rare entity are presented and discussed along with various dura based tumours.

Intracranial solitary fibrous tumors: imaging findings in 6 consecutive patients

BACKGROUND AND PURPOSE

Intracranial solitary fibrous tumors (ISFTs) are rare mesenchymal neoplasms originating in the meninges. The aim of this study was to describe the CT, MR imaging, and angiographic features of the solitary fibrous tumor and to identify imaging characteristics.

MATERIALS AND METHODS

We retrospectively reviewed CT, MR, and angiographic findings in 6 cases of ISFT. We evaluated the size, shape, and location of the tumor; the internal content and margin of the lesion; the pattern of enhancement; and the change of the adjacent structures. Density on noncontrast CT scans, signal intensity on MR images, and angiographic features were also documented.

RESULTS

Each lesion appeared as a discrete extra-axial mass (size, 3-7 cm; mean, 5 cm). Five lesions were entirely solid, and 1 had peritumoral cyst. All 5 of the noncontrast CT scans showed hyperattenuated masses, and the tumors exhibited marked heterogeneous enhancement. No lesion contained calcification, and 2 cases showed bone invasions. On the MR images, 4 lesions showed mixed signal intensity on T2-weighted imaging. All of the lesions revealed marked heterogeneous enhancement. All of the tumors had thickening of the meninges adjacent to the tumor. Angiography showed delayed tumor blushing in all, and 3 of them had dysplastic dilation of the tumor vessels.

CONCLUSION

Although there are no pathognomonic imaging findings, some imaging features, such as the "black-and-white mixed" pattern on T2-weighted images and marked heterogeneous enhancement, might be helpful in the diagnosis of intracranial solitary fibrous tumor.

Meningeal solitary fibrous tumour in a child

INTRODUCTION

Meningeal solitary fibrous tumour is a relatively recent pathological entity that has rarely been described in children. With radiological techniques, it cannot be distinguished from meningiomas, and the diagnosis has to be confirmed histologically.

CASE REPORT

We discuss the possible histogenesis of this tumour and the need for recognizing this lesion as a separate entity. We report the case of a 12-year-old boy who developed a meningeal solitary fibrous tumour; the main clinical symptoms were progressive headaches for a long period and recent transient hemiparesis.

CONCLUSION

This child presents an uneventful evolution without additional therapy 3.5 years after surgery.

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.

Solitary fibrous tumor in the thigh: review of the literature

Solitary fibrous tumors (SFT) of extremities, especially the thighs are very rare. Despite SFTs are generally benign, well-circumscribed soft tissue tumors new cases should be presented and followed up carefully to monitor their biological behavior. In general for tumor classification a biopsy is state of the art. Histological including immunohistochemical patterns for SFTs are defined. MRI and ultrasound are not sufficient for differential diagnosis. Once property identified and defined by size and location, resection with intact tumor capsule may result in full recovery of the patient. Reviewing the literature there are no validated reasons for a wider resection. The current patient was a 41-year-old male. Four years after an arthroscopy of the left knee the patient has been suffering an ongoing swelling of the lateral thigh. Because MRI scan data suggested a synovial sarcoma a biopsy was performed. The tumor was classified as a benign SFT. The diagnosis based on histological findings and the presence of the positive immunohistochemical markers Vimentin, CD34, and CD99. The complete tumor resection with intact capsule was achieved in a final operation. Clinical and in MRI after 54-month outcome period there were no local recurrences.

Recurrent solitary fibrous tumour in the cerebellopontine angle

Solitary fibrous tumours (SFT) of the central nervous system are rare. They resemble meningioma in clinical presentation, imaging features and appearance at surgery. Schwannoma, hemangiopericytoma and other spindle cell mesenchymal neoplasms should also be considered in the differential diagnosis. Although the histogenesis of this tumour is still debated, strong CD34 reactivity of the tumour cells suggests that SFT is mesenchymal. We present the clinical, radiological, and pathological features of an SFT located in the cerebellopontine angle (CPA). A 55-year-old female presented with 6 months of headache. The MRI scan showed a contrast enhancing ovoid mass in the left CPA. At craniotomy, the tumour was completely resected. Histolopathological diagnosis was of meningioma. Three years later, the symptoms recurred and an MRI scan demonstrated tumour recurrence. A repeat craniotomy was performed and the lesion was again completely excised. Tumour morphology on histopathology and immunoreactivity for CD34 of the tumour cells supported the diagnosis of SFT. Review of the original tumour also disclosed immunoreactivity for CD34. Ki67 labeling indices were less than 1% in both tumours.

A Highly Vascular Intracranial Solitary Fibrous Tumor Treated with Radiotherapy and Toremifene: Case Report

OBJECTIVE AND IMPORTANCE:

A case of an unusual intracranial solitary fibrous tumor with features of high vascularity and resultant difficulty at resection is presented. The use of surgery, radiotherapy, and toremifene has been successful with no recurrence after 18 months.

CLINICAL PRESENTATION:

A 33-year-old male patient presented with a 1-year history of loss of vision on the left side and a 3-month history of headache and lethargy. Magnetic resonance imaging showed a lobulated mass (7.6 × 4.5 cm) in the left temporal fossa and left parasellar, sellar, and suprasellar regions, with a “dural tail” more typical of meningioma. Vascular supply was from both the internal carotid arteries and the left middle meningeal artery, precluding embolization.

INTERVENTION:

At the time of the craniotomy, a highly vascular tumor was found. Intraoperative hemorrhage limited resection to 20% of the tumor. The histological diagnosis was of a solitary fibrous tumor with an unusually angiomatoid architecture. After the operation, radiotherapy and toremifene were administered. A dramatic reduction in the size of the tumor was seen with no recurrence to date.

CONCLUSION:

The use of surgery, radiotherapy, and toremifene in treatment of a vascular intracranial solitary fibrous tumor has been successful and warrants further research.

Atypical presentations of solitary fibrous tumors of the central nervous system: an analysis of unusual clinicopathological and outcome patterns in three new cases with a review of the literature

Central nervous system (CNS) solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms recognized less than a decade ago. Approximately 60 cases of SFT have been reported in the central nervous system. We describe three atypical SFTs of the CNS, two intracranial and one within the spine. One intracranial SFT arose from the sella turcica and expanded into the suprasellar areas. It relapsed twice during the 3 years following partial resection, and the MiB 1 labeling index steadily increased without obvious malignant transformation. The second SFT arose from the confluence of the sinuses, widely invaded the lateral sinus and adjacent bones, had a low MiB 1 index and has not recurred after 5 years. The intraspinal tumor occurred at T5-T7 in a patient with multiple café-au-lait spots, was predominantly myxoid and developed a second similar lesion at S3-S5 14 years later. The MiB 1 index was lower in the second tumor. Immunohistochemistry confirmed that all were SFTs. These atypical presentations gave us an opportunity to provide further information about the natural histological course of CNS SFTs.

Solitary Fibrous Tumor of the Thoracic Spinal Cord-Case Report-

A 63-year-old woman presented with a rare case of primary solitary fibrous tumor (SFT) occurring in the extramedullary thoracic spinal cord. T1-weighted magnetic resonance (MR) imaging showed the tumor as a mildly hypointense area with homogeneous enhancement by gadolinium. T2-weighted MR imaging showed a hypointense mass with peritumoral edema. The tumor arose from one of the posterior spinal roots, with no attachment to the dura. The tumor was clearly circumscribed from the surrounding cord tissue and easily removed. Histological examination showed the tumor predominantly consisted of spindle cells separated by abundant collagen matrix fibers. Tumor cells were strongly positive for vimentin and CD34, but negative for glial fibrillary acidic protein, S-100 protein, epithelial membrane antigen, myelin basic protein, and keratin. SFT should be considered in the differential diagnosis of spindle cell central nervous system neoplasms, although SFT is extremely rare in the spinal cord.

Recurrent intracranial solitary fibrous tumor with cerebrospinal fluid dissemination

✓ Solitary fibrous tumor (SFT) is a benign and rare neoplasm. To date, only 37 patients with intracranial SFTs have been reported. Although a number of the tumors were recurrent and some later underwent malignant transformation, none of these lesions progressed to cerebrospinal fluid (CSF) dissemination. In this paper the authors report a case of SFT in which the lesion recurred several times and ultimately was disseminated by the CSF. The patient was a 63-year-old woman with multiple intracranial and spinal tumors. Fifteen years before this presentation, at the age of 48 she had been hospitalized for resection of a falcotentorial tumor. During the ensuing 15 years she underwent multiple surgeries and sessions of radiation therapy for recurrent lesions. The exclusive location of her tumors in the subarachnoid space at the end of this 15-year period indicate CSF dissemination of the tumor.

The tumor that was resected when the patient was 48 years old and the latest resected lesion were analyzed by performing immunohistological CD34, epithelial membrane antigen, vimentin, S100 protein, and reticulin staining, and determining the MIB-1 labeling index (LI). Most of the results were identical, and both tumors were diagnosed as SFT according to a staining pattern that showed a strong and diffuse positive reaction for CD34. Nevertheless, the authors noted that the MIB-1 LI increased from less than 1% in the original tumor to 13% in the latest tumor. The increased proliferation of MIB-1 indicates that the malignant transformation could have occurred during tumor recurrence with CSF dissemination.

Solitary Fibrous Tumor of the Spinal Cord: Case Report and Review of the Literature

OBJECTIVE AND IMPORTANCE:

A solitary fibrous tumor (SFT) is a rare neoplasm of probable mesenchymal origin that was first reported in the pleura but can occur in different sites. Only six cases of SFT arising from the spinal cord have been reported.

CLINICAL PRESENTATION:

We report a case of primary SFT occurring in the thoracic spinal cord in a 64-year-old man with Brown-Séquard syndrome. Magnetic resonance imaging revealed an intradural mass at the level of T2–T3.

INTERVENTION:

Total T2–T3 laminectomies were performed. The tumor appeared to be adherent to the right lateral aspect of the cord but not attached to the meninges. On histological examination, the tumor exhibited spindle cell proliferation with abundant dense collagen but without a hemangiopericytomatous pattern. Immunohistochemically, the tumor cells were reactive with CD34 and vimentin only.

CONCLUSION:

We report a rare case of SFT occurring in the thoracic spinal cord. Histologically and immunohistochemically, we confirmed the diagnosis of SFT. Low signal intensity on T1- and T2-weighted images corresponded to the histological findings. When a spinal cord tumor exhibits a signal pattern similar to this, SFT should be included in the differential diagnosis. Because of the rarity of reports on this condition, the clinical manifestations and course of SFT of the spinal cord are unknown, and careful long-term follow-up is recommended.

Intramedullary and extramedullary solitary fibrous tumor of the cervical spine

✓ Solitary fibrous tumor is a spindle cell tumor deriving from mesenchymal cells that arises most commonly in the pleura. Only very recently has this tumor been reported in the spine. A solitary fibrous tumor strongly resembles other spindle cell neoplasms of the spine and may be an unrecognized entity if not routinely considered in the differential diagnosis of spinal neoplasms. The authors report an unusual intra- and extramedullary location for a solitary fibrous tumor of the cervical spine. Findings in this case and a comprehensive review of the literature indicate that solitary fibrous tumors can originate from various spinal anatomical substrates and mimic both intra- and extramedullary tumor types.

Solitary Fibrous Tumor of the Cerebellopontine Angle With Salivary Gland Heterotopia

We report the unique association of a solitary fibrous tumor of the cerebellopontine angle with ectopic salivary gland tissue in a 53-year-old woman. The patient, diagnosed 21 years earlier with a right cerebellopontine angle fibrous meningioma, presented with a recurrent mass, which, upon surgical removal, showed features of a solitary fibrous tumor. Strong and diffuse immunoreactivity to CD34 and BCL-2 and a negative epithelial membrane antigen immunostain confirmed the diagnosis. Admixed with the spindle cell neoplasm, a bland glandular element composed of small glands and variably dilated tubules was noted. The vague tubuloacinar arrangement of the glands and the presence of acinar cells with a granular, periodic acid-Schiff-positive, basophilic cytoplasm, resembling serous type acini, were features of benign, although ectopic, salivary gland tissue. The presence of a myoepithelial cell layer, surrounding some of the acini and highlighted by the smooth muscle actin immunostain, strengthened this interpretation.