Solitary fibrous tumor

A Rare Case of a Primary Leiomyoma of the Clivus in an Immunocompetent Patient and a Review of the Literature Regarding Clival Lesions

Leiomyomas are common lesions that are usually located in the genitourinary and gastrointestinal tracts. Primary leiomyomas at the skull base are uncommon. They are composed of well-differentiated smooth muscle cells without cellular atypia. The diagnosis of a leiomyoma has to be confirmed by immunohistochemistry. The tumor tissue is immunoreactive for SMA, S100 and cytokeratin. Leiomyomas mainly occur in immunocompromised patients. Most tumor tissues are positive for EBV. The presented case is that of a 56-year-old immunocompetent woman with a tumor on the clivus. The radiological images suggested chordoma or fibrous dysplasia. Transnasal transsphenoidal surgery was performed. The tumor tissue consisted of well-differentiated smooth muscle cells with elongated nuclei. Immunohistochemistry revealed a positive reaction for desmin, SMA and h-Caldesmon and a negative reaction for S100, beta-catenin, PGR and Ki67. The leiomyoma diagnosis was subsequently established. To the best of our knowledge, the case of a primary leiomyoma on the clivus of an immunocompetent patient is the first to be described. We also extensively reviewed the literature on the immunohistopathological and radiological differential diagnosis of clival lesions.

Solitary fibrous tumor with aneurysmal bone cyst–like change in the middle cranial fossa: illustrative case

BACKGROUND

Solitary fibrous tumor (SFT) is a rare mesenchymal tumor known for its propensity for recurrence and metastasis. Furthermore, aneurysmal bone cyst (ABC) is a benign osteolytic lesion. ABC-like areas can be seen in bone tumors that have undergone hemorrhagic cystic change. They are formed by disruptions in the osseous circulation caused by the associated lesion. The most common associated lesions are giant cell tumor, chondroblastoma, osteoblastoma, osteosarcoma, chondromyxoid fibroma, and fibrous dysplasia. There has been no reported case of SFT being the associated lesion.

OBSERVATIONS

A 42-year-old woman presented with a 6-month history of headache and impaired memory. Radiological examinations revealed a 50-mm cystic lesion with multiple fluid levels arising from the left temporal bone. Total resection of the tumor was conducted, and postoperative course was uneventful. Histopathological examination was consistent with SFT with ABC-like change.

LESSONS

This is the first documented case of SFT with ABC-like change in the cranial fossa. This should be considered a differential diagnosis when treating a lesion in the cranial fossa, such as in this case, to achieve complete resection of the tumor and have close follow-up postoperatively.

Solitary fibrous tumour of cervical spinal cord

Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms of fibroblastic origin. They commonly arise from visceral pleura, but also arise from nonserosal sites such as meninges, central nervous system parenchyma, and spinal cord. In the spinal cord, SFTs commonly arise from the thoracic spinal cord, followed by cervical spinal cord, lumbar spinal cord, and sacrum. Histologically, SFTs can be similar to hemangiopericytoma, schwannoma, fibrous meningioma, fibroma, gliofibroma, and ependymoma. Immunohistochemistry (IHC) plays an important role in differentiating SFTs from other identical tumors. Here, we report a rare case of SFT of the cervical spinal cord, which was initially reported as hemangiopericytoma, and the diagnosis of SFT was confirmed by IHC.

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.

The Importance of STAT6 in a Schwannoma-like Grade III Solitary Fibrous Tumor/Hemangiopericytoma Located in the Cerebellopontine Angle and Meckel's Cave

BACKGROUND

Hemangiopericytoma (HPC) is a rare mesenchymal tumor of the brain that occurs in the central nervous system as a solitary fibrous tumor. Surgical treatment of HPC is known to be beneficial, but results on the role of complete resection and adjuvant radiation are conflicting. However, it is often difficult to detect a central nervous system solitary fibrous tumor/HPC before surgery. We describe a presumed left trigeminal schwannoma that was histopathologically shown to be an HPC.

CASE DESCRIPTION

A 65-year-old man presented with paresthesia of the second and third branches of the left trigeminal nerve. Magnetic resonance imaging showed a tumoral lesion in the left cerebellopontine angle and Meckel's cave. We suspected a schwannoma and performed surgery, which resulted in only a partial resection because of tumor bleeding and unexpected intraoperative histologic findings. We could not achieve a definitive diagnosis. However, we observed local recurrence and disseminated lesions 5 and 6.5 years later, respectively. We performed a second surgery and were able to definitively diagnose the lesion as a grade III HPC based on the positive expression of STAT6 during immunostaining.

CONCLUSIONS

As solitary fibrous tumor/HPC requires gross total resection for effective resolution, it is imperative to consider it in the differential diagnoses of similar tumors. If an unusual pathologic image is found, we recommend rapid immunostaining for STAT6 to reach a definitive conclusion regarding the tumor type. This case highlights the importance of considering HPC when screening or diagnosing central nervous system lesions, especially in this rare location.

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.

Meningioma mimics: five key imaging features to differentiate them from meningiomas

There are a wide variety of intracranial mass lesions, both benign and malignant, which can closely mimic meningioma on imaging. We present five characteristic imaging features that can alert the radiologist to consider other differential diagnoses. Of the five imaging characteristics that were rarely seen in meningiomas, but common and specific for meningioma mimics, absence of dural tail is the most common (83.7%). Homogeneous T2 hyperintensity or T2 hypointensity are seen in nearly half of meningioma mimics and osseous destruction and leptomeningeal extension are present in 40.5% and 21.6% of meningioma mimics, respectively. The distinction between meningioma and its mimics is important because a large portion of the meningioma mimics requires substantially different clinical and surgical management.

Intracranial Solitary Fibrous Tumor

Solitary fibrous tumours are rare mesenchymal spindle-cell tumours that occur most often in the visceral pleura or liver. If they occur intracranially, they are extra-axially located and develop from the meninges. In those cases, the differential diagnosis has to be made with other intracranial extra-axial-located tumours, such as meningeoma and hemangiopericytoma. We report a 32-year-old woman with an intracranial solitary fibrous tumour and review the latest literature regarding the imaging characteristics of this tumour.

Intracranial Cystic Myofibroblastoma: a Case Report with Literature Review

BACKGROUND

Myofibroblastoma is a rare benign soft tissue tumor comprised of contractile myiod cells mostly in mammary gland. Only 4 prior cases arising in the central nervous system have been reported in the literature. We present a case of myofibroblastoma with a cystic component.

CASE DESCRIPTION

The patient is a 76-year-old man with a history of Parkinson disease. The tumor was found incidentally after a minor fall. Magnetic resonance imaging revealed a 6.7-cm well-circumscribed, partly cystic mass with a 2.4-cm calcified central nodule located at the left sylvian fissure. The frontal dural base showed avid enhancing after gadolinium injection. Gross total resection was achieved. The tumor was marked by dense collagenous tissue and bland spindled cells in pathology review. The spindled cells demonstrated positive staining with antibodies to CD34, estrogen receptor, and smooth muscle actin. A blush of immunoreactivity is observed in scattered cells with antibody to progesterone receptor. Patient recovered well postoperatively.

CONCLUSIONS

This is a rare condition of a benign soft tissue tumor of mammary gland presented primarily in the brain. The literature on myofibroblastomas arising in the central nervous system is reviewed.

Intradural solitary fibrous tumor of the lumbar spine: a distinctive case report

Background. Solitary fibrous tumors are ubiquitous mesenchymal neoplasms of putative fibroblastic origin. They were originally described in the pleura but subsequently have been reported in many extraserosal sites. Solitary fibrous tumors may also occur in the meninges, central nervous system parenchyma, and spinal cord. Case. A 67-year-old male patient with progressive lower extremity weakness, urinary urgency, and sexual dysfunction has been admitted to our hospital. On his lumbar MRI, we detected an intradural lesion posterior to the L3 vertebral corpus. We resected the lesion by L3 total laminectomy. Immunohistological findings revealed strong and diffuse immunopositivity with vimentin, CD34, and bcl-2. Ki-67 proliferation index was 5–8%. We did not detect any recurrence 12 months after his operation. Conclusion. SFT is mostly seen in young and middle-aged patients and should be considered among differential diagnosis in cases suffering from pain, hypoesthesia, and urinary dysfunction. Gross total resection should be primary treatment. Tumors that have high Ki-67 labeling should be followed up for potential recurrences.

Solitary fibrous tumor of the lumbar spine: the great mimicker-report of the fifth case

Solitary fibrous tumor (SFT) is a rare neoplasm occurring in the central nervous system. It rarely occurs in the spine. This paper reports the fifth case of SFT in a 34-year-old female and focusses on differential diagnosis and importance of surgical treatment.

Meningeal myofibroblastoma in the frontal lobe: A case report

Myofibroblastoma is a benign tumor composed of spindle cells in clusters and fascicles. To date, only three cases of intracranial myofibroblastoma have been reported. The present study reports the case of a 47-year-old female with meningeal myofibroblastoma. The patient had a history of ovarian cyst resection and presented with paroxysmal mild headaches that had been apparent for 4 years. Magnetic resonance imaging disclosed a well-circumscribed mass in the left frontal lobe. A resection of the mass was performed. Abundant fascicular clusters of spindle- and oval-shaped cells were found by conventional histopathology. Immunohistochemical staining demonstrated that these cells were strongly positive for smooth muscle actin, weakly positive for epithelial membrane antigen and negative for cluster of differentiation (CD)117, CD34, S-100 or desmin, with a Ki-67 index of >10%. These results supported the diagnosis of myofibroblastoma. No recurrence of the mass was found during the 24-month follow-up period. Overall, the patient exhibited a rare type of meningeal neoplasm. Resection of the tumor proved to be successful and no recurrence were found. Histopathological and immunohistochemical staining is crucial to form a diagnosis. To the best of our knowledge, the present study is the first to show the presence of myofibroblastoma in the left frontal lobe.

Cellular solitary fibrous tumor (hemangiopericytoma) with anaplasia at cerebellopontine angle--a case report

Cellular solitary fibrous tumor is currently considered a synonym for hemangiopericytoma, as it became increasingly clear that the morphological and immunohistochemical features that separate these two entities have become tenuous, and evidence for a unifying concept has emerged. Furthermore, as no evidence of pericytic differentiation is given in most cases of hemangiopericytoma, this diagnostic term is waning in popularity. We present here a case of cellular solitary fibrous tumor in a 22-year-old man. Neuroimaging revealed a right cerebellopontine angle tumor. Most of the tumor was cellular although some less cellular areas were seen. Sinusoidally dilated large vessels, including staghorn type, were seen. Nuclear pleomorphism and increased mitotic activity (5 mitosis/10 high power field) were regarded as evidence of anaplasia. Diffuse CD34 immunoreactivity and focal positivity for Factor XIIIa were seen in the tumor, which was negative for EMA and S100. The tumor also displayed rich reticulin network. Solitary fibrous tumor at cerebellopontine angle is rare, and 20 such cases (five reported as hemangiopericytoma) have been reported in the English literature.

Solitary fibrous tumor of the central nervous system: a clinicopathologic study of 24 cases

OBJECTIVE

Solitary fibrous tumor is a rare, spindle-cell benign mesenchymal neoplasm and has a high recurrence rate. In this study, we reviewed our experience in the diagnosis and treatment of 24 patients with central nervous system solitary fibrous tumors.

METHODS

Clinical data were retrieved from the medical records. Prognosis was assessed by clinic service and telephone interview. The specimens were stained with hematoxylin and eosin. Immunohistochemistry for CD34, CD99, EMA, HMB-45, Bcl-2, vimentin, GFAP, S-100, MBP, CK and MIB-1 was performed in all cases. Distributions of time to progression and recurrence were estimated using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

The 24 patients included 13 men and 11 women with a median age of 49.0 years. The most frequent initial symptoms were headache, dizziness, unstable walk and hearing loss. The most common location was cerebellar pontine angle (n = 6). Surgery reached gross total removal for 18 patients but subtotal removal for six patients on initial operation. Histopathologic examination showed spindle to oval cells were disposed in wavy fascicles between prominent, eosinophilic bands of collagen. Dense bands of collagen appeared in cross section as minute nodules that separated individual tumor cells. Cellular areas with a partial hemangiopericytoma pattern were noted in six cases. Atypical presentations were shown on initial operation in three cases. CD34, CD99 and vimentin were 100% positive; but EMA, CK, MBP, HBM-45 and GRAP were 100% negative. The positive in Bcl-2, RF and S-100 was 89%, 85% and 26%, respectively. Follow-up information was available for 23 patients. The median follow-up period was 36.0 months. Nine patients recurred and one patient died from the progression. Incomplete surgical resection was significantly associated with recurrence (p = 0.010). MIB-1 labeling index in recurrence was higher than in no recurrence (6.0% versus 3.4%, p = 0.029). All treated with subtotal removal only had subsequent tumor recurrence or progression; however, the two patients who were administered adjuvant radiosurgery after subtotal removal did not recur or progress. Adjuvant radiosurgery seemed to improve the prognosis (p = 0.028).

CONCLUSIONS

Solitary fibrous tumor is a rare mesenchymal tumor with a propensity to recur. The most affected area is the cerebellopontine angle. Immunohistochemistry should be used to differentiate solitary fibrous tumor from other tumors. The extent of resection, MIB-1 labeling index and some anaplastic features might be predictive for recurrence. Postoperative radiosurgery might be an option in incompletely resected solitary fibrous tumor. Regular and long-term follow-up remains mandatory to monitor recurrence.

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.