Clinical and Radiographic Features for Differentiating Solitary Fibrous Tumor/Hemangiopericytoma From Meningioma

Intracranial solitary fibrous tumor/hemangiopericytomas: a clinical analysis of a series of 17 patients

OBJECTIVE

Solitary fibrous tumors (SFTs) and haemangiopericytomas (HPCs) are rare mesenchymal tumors in central nervous system (CNS). Although progressed recognition to the diagnosis and treatment of SFT/HPCs, it still remains many confusions regarding on its occurrence, aggressive evolution, malignant transformation, dedifferentiation phenomenon, distant metastasis and unpredictable propensity.

PATIENTS AND METHODS

Seventeen cases of CNS SFT/HPCs who underwent surgical treatment from January 2010 to December 2020 were collected in the authors' institute. Clinical, radiological, pathological data and followup details were reviewed in all cases.

RESULTS

The age of this series was 41-73 years old. Seven cases located subtentorially, five cases originated from middle skull base and four in supratentorial. MRI shows iso-signal intensity on T1WI, and heterogeneous slightly long/short signal on T2WI. There is significant contrast after gadolinium-enhancement. It is easy to be misdiagnosed before surgery. The positive rate of nuclear STAT6 is 94.12%, higher than CD34 (87.5%). Eight patients were grade I, eight grade II and one in grade III. Five cases developed tumor relapse, in which two cases had local intracranial recurrence combined with dissemination and metastasis of cerebrospinal fluid in the spinal canal, accompanied by pathological malignant transformation, and another one occurred blood metastasis.

CONCLUSIONS

CNS SFT/HPCs are rare intracranial tumors with unpredictable propensity. Gross total resection is critical to its overall clinical prognosis. Given its potential recurrence and malignant transition, adjuvant radiotherapies are recommended when necessary, and long-term follow-up is indispensable. The underlying molecular biological mechanisms are still needed to be further exploration.

The role of tumor parenchyma and brain cortex signal intensity ratio in differentiating solitary fibrous tumors and meningiomas

BACKGROUND

Solitary fibrous tumors (SFT) and meningiomas (MA) have similar clinical and radiographic presentations but require different treatment approaches and have different prognoses. This emphasizes the importance of a correct preoperative diagnosis of SFT versus MA.

OBJECTIVE

In this study, investigated the differences in imaging characteristics between SFT and MA to improve the accuracy of preoperative imaging diagnosis of SFT.

METHODS

The clinical and imaging data of 26 patients with SFT and 104 patients with MA who were pathologically diagnosed between August 2017 and December 2022, were retrospectively analyzed. The clinical and imaging differences between SFT and MA, as well as between the various pathological grades of SFT, were analyzed.

RESULTS

Age, gender, cystic change, flow void phenomenon, yin-yang sign, lobulation, narrow base, tumor/cortex signal ratio (TCSR) > 1.0 in T1-weighted imaging (T1WI), TCSR ≥ 1.1 in T2-weighted imaging (T2WI), peritumoral edema, and absence of dural tail sign varied between SFT and MA. As per the receiver operating characteristic (ROC) curve analysis, TCSR > 1 in T1WI has the maximum diagnostic accuracy for SFT. Cranial or venous sinus invasion had a positive effect on SFT (Grade III, World Health Organization (WHO) grading).

CONCLUSION

Among the many radiological and clinical distinctions between SFT and MA, TCSR ≥ 1 exhibits the highest predictive efficacy for SFT; while cranial or venous sinus invasion may be a predictor of WHO grade III SFT.

Solitary Fibrous Tumor of the Central Nervous System: A Report of Two Cases with Emphasis on Diagnostic Pitfalls

Solitary fibrous tumor (SFT) is a rare primary central nervous system neoplasm that usually presents as a dural-based mass. Awareness of the entity is limited by the rarity of the tumor which renders it prone to misdiagnosis. We present two cases of SFT located in the right parafalx and intraventricular region. The cases were classified as WHO grade 1 and grade 2, respectively. The present study discusses the radiological, histomorphological, and immunohistochemical features of SFT, with emphasis on potential diagnostic pitfalls that may lead to erroneous diagnosis.

Unique magnetic resonance spectroscopy profile of intracranial meningiomas compared to gliomas: a systematic review

BACKGROUND AND PURPOSE

The goal of this study was to systematically review the metabolic profile of meningiomas using magnetic resonance spectroscopy in comparison to gliomas, as measured by mean metabolite ratios.

METHODS

Following the PRISMA guidelines, a systematic literature review was performed using the PubMed, Ovid Embase, Web of Science, and the Cochrane databases from inception to May 2021. Studies were selected based on predetermined inclusion and exclusion criteria.

RESULTS

Eight studies were ultimately selected with 207 patients included. Fifty-nine patients were diagnosed with meningioma (age = 48.4, 66.7% female) and 148 patients diagnosed with glioma (age = 56.4, 49.2% female). Three studies reported elevated Cho/Cr in meningiomas compared to gliomas (5.71 vs. 1.46, p < 0.05, 7.02 vs. 2.62, p < 0.05, and 4.64 vs. 2.52, p = 0.001). One study reported Ala/Cr to be significantly elevated in meningiomas compared to gliomas (1.30 vs. undetectable, p < 0.001). One study reported myo-Inositol/Cr to be significantly elevated in meningiomas in comparison to gliomas (1.44 vs. 1.08, p < 0.05). One study reported Glu/Cr to be significantly elevated in meningiomas in comparison to gliomas (3.47 vs. 0.89, p = 0.002). Two studies reported Cho/NAA to be significantly elevated in meningiomas in comparison to gliomas (4.46 vs. 2.6, p = 0.004, and 5.8 vs. 2.55, p < 0.05). Two studies reported NAA/Cr was significantly elevated in gliomas compared to meningiomas (undetectable vs. 1.54, p < 0.001 and undetectable vs. 0.58, p < 0.05).

CONCLUSIONS

Significant differences in metabolite ratios between tumor types were reported in Cho/Cr, Ala/Cr, Glu/Cr, Cho/NAA, myoI/Cr and NAA/Cr between meningiomas and gliomas.

Complete Resection of a Torcular Herophili Hemangiopericytoma without Sinus Reconstruction: A Case Report and Review of the Literature

A 78-year-old woman presented to the emergency department with mild headaches and a sudden onset of blurred vision. Computerized tomography scan and magnetic resonance imaging showed what was described at first as a meningioma invading and occluding the torcular Herophili, the posterior third of the superior sagittal sinus and the proximal part of the right transverse sinus. Gross total resection of the tumor was performed without reconstructing dural sinuses. The patient was discharged home without new neurological deficit. Histopathology was in favor of a hemangiopericytoma Grade II World Health Organization (WHO). Total body positron emission tomography [18F]fluorodeoxyglucose found no secondary location. Radiotherapy was planned post-operatively.

Update on meningioma: Clinical-radiological and radio-pathological correlation

Meningiomas are tumors that originate in the arachnoid villi and are the most common non-glial neoplasm in the central nervous system. The clinical manifestations associated with meningioma depend, fundamentally, on its location. The location in the cerebral convexity is the most frequent, especially in the frontal lobes, manifesting with headache, motor disturbances, seizures and even neurocognitive disorders. There are 15 histologic subtypes of meningioma and three histologic grades. Within these, grades two and three have a worse prognosis and a higher rate of recurrence, as well as a radiological behavior that is generally more aggressive. Although there are some imaging features that can suggest a specific subtype, the definitive diagnosis will always require histological/molecular confirmation.

Radiological Differentiation Between Intracranial Meningioma and Solitary Fibrous Tumor/Hemangiopericytoma: A Systematic Literature Review

BACKGROUND

Intracranial solitary fibrous tumor (SFT) is characterized by aggressive local behavior and high post-resection recurrence rates. It is difficult to distinguish between SFT and meningiomas, which are typically benign. The goal of this study was to systematically review radiological features that differentiate meningioma and SFT.

METHODS

We performed a systematic review in accordance with PRISMA guidelines to identify studies that used imaging techniques to identify radiological differentiators of SFT and meningioma.

RESULTS

Eighteen studies with 1565 patients (SFT: 662; meningiomas: 903) were included. The most commonly used imaging modality was diffusion weighted imaging, which was reported in 11 studies. Eight studies used a combination of diffusion weighted imaging and T1- and T2-weighted sequences to distinguish between SFT and meningioma. Compared to all grades/subtypes of meningioma, SFT is associated with higher apparent diffusion coefficient, presence of narrow-based dural attachments, lack of dural tail, less peritumoral brain edema, extensive serpentine flow voids, and younger age at initial diagnosis. Tumor volume was a poor differentiator of SFT and meningioma, and overall, there were less consensus findings in studies exclusively comparing angiomatous meningiomas and SFT.

CONCLUSIONS

Clinicians can differentiate SFT from meningiomas on preoperative imaging by looking for higher apparent diffusion coefficient, lack of dural tail/narrow-based dural attachment, less peritumoral brain edema, and vascular flow voids on neuroimaging, in addition to younger age at diagnosis. Distinguishing between angiomatous meningioma and SFT is much more challenging, as both are highly vascular pathologies. Tumor volume has limited utility in differentiating between SFT and various grades/subtypes of meningioma.

Solitary fibrous tumor of the central nervous system invading and penetrating the skull: A case report

Solitary fibrous tumor (SFT) of the central nervous system is a rare spindle cell tumor of mesenchymal origin. The present study reports the case of a 44-year-old male patient with SFT. Magnetic resonance imaging demonstrated that the majority of the intracranial tumors exhibited uneven low signals on T1-weighted imaging (T1WI) and low mixed signals on T2WI, and there was an enhancement on enhanced scanning. Furthermore, the distal part of the left occipital lobe exhibited hypersignals on T1WI and T2WI, and this was significantly enhanced following enhanced scanning. The lower part of the scalp exhibited low signals on T1WI and high signals on T2WI, and there was no notable enhancement following enhanced scanning. Magnetic resonance spectroscopy demonstrated an elevated choline/creatine peak in the solid part of the tumor. Under the microscope, the tumor exhibited characteristic 'staghorn-shaped' blood vessels. As SFT is difficult to differentially diagnose via imaging, immunohistochemical analysis of CD34, vimentin and signal transducer and activator of transcription 6 was performed for the definitive diagnosis of SFT. Of note, surgical resection was the preferred treatment for SFT; however, due to the rarity of the tumor, subsequent adjuvant therapy and prognosis require further investigation.

Orbital solitary fibrous tumours: clinicopathological characteristics and recurrence prediction

BACKGROUND

SFTs are thought to have an unpredictable clinical course and currently have no recognized prognostic criterion. Our study aimed to determine the relationship between clinicopathological characteristics and the prognosis of patients with orbital SFTs.

METHODS

The clinicopathological features of these patients were extracted from clinical records. The relationships between these features and prognosis were analysed.

RESULTS

The positive rates of CD34, CD99, Blc2, and STAT6 expression were 90.3%, 90.3%, 83.9%, and 100%, respectively. The tumour recurrence rate was 38.7%. A higher recurrence rate was observed in patients with Ki67 index ≥ 5 (56.25% vs. 20%, P = 0.038).

CONCLUSION

A Ki67 index ≥ 5 was an effective parameter for predicting tumour recurrence of orbital SFTs. Close follow-up is needed for these patients.

[Recurrent petrosal tumor: meningioma or solitary fibrous tumor?]

Intracranial meningeal solitary fibrous tumors (SFT) originating from mesenchymal tissue are much less common than those with lesions of the visceral pleura or liver and were isolated as a nosological form only in 1996. These tumors are identical in clinical manifestations, MRI and light microscopy data to meningiomas. The pathognomonic difference of SFT, according to the 5th edition of the WHO classification, is the detection of overexpression of the protein encoded by the STAT6 gene. Estimation of other immunohistochemical markers is variable. At the same time, SFT has a tendency to more frequent recurrence and delayed malignancy. Transitional forms are possible. To form a clearer nosological outline of the SFT, it is necessary to accumulate clinical observations. A case of a giant meningioma of the posterior cranial fossa, which recurred 18 years after total removal at a 5-year annual control, is presented. Light microscopy of both primary and recurrent tumors revealed fibrous meningioma (WHO GI). Immunohistochemically revealed diffuse overexpression of CD34 and CD99. Determining the expression of the STAT6 protein was not technically possible. This case is regarded as a meningioma of the posterior surface of the pyramid of the temporal bone, growing into the cavity of the IV ventricle, with late recurrence without malignancy, with specific immunohistochemical profile.

Solitary fibrous tumors: Clinical and imaging features from head to toe

Solitary fibrous tumors (SFTs) are rare fibroblastic mesenchymal tumors that are usually benign with variable malignant potential. They can develop in any organ due to their spindle cell origin. The exact etiology of solitary fibrous tumors is unknown. The majority of SFTs are benign with 10-30% of them exhibiting aggressive and malignant features. The aggressiveness of this type of tumor is not associated with its histological features, which makes surgical resection the treatment of choice. We will review the clinical and radiological features and possible differential diagnoses of SFTs according to their anatomical sites following the World Health Organization 2020 classification.

A collision tumor of solitary fibrous tumor/hemangiopericytoma and meningioma: A case report with literature review

An intracranial collision tumor is a rare lesion composed of two histologically different neoplasms in the same anatomic location. Even more rare is the collision tumor of a solitary fibrous tumor/hemangiopericytoma (SFT/HPC) and meningioma. The patient was a 46-year-old woman who had a 40 × 35 × 30-mm mass in the vermis of the cerebellum. Histologically, the mass consisted of two different components. One component showed the morphology of meningioma (World Health Organization (WHO) grade I), and the other component exhibited small round cell proliferation with hypercellular density, which was revealed to be SFT/HPC (WHO grade III) based on STAT6 immunohistochemistry. STAT6 showed completely different immunohistochemistry results in these two components (nuclear-negative in meningioma and nuclear-positive in SFT/HPC). Since these two neoplasms are associated with different prognoses, they should be distinguished from each other. When meningioma and an SFT/HPC-like lesion are identified morphologically, it is important to recognize the presence of such a collision tumor composed of meningioma and SFT/HPC, and identify the SFT/HPC component by employing STAT6 immunohistochemistry.

Primary central nervous system lymphomas with massive intratumoral hemorrhage: Clinical, radiological, pathological, and molecular features of six cases

Primary central nervous system lymphomas (PCNSLs) rarely exhibit intratumoral hemorrhage. The differential diagnosis of hemorrhagic neoplasms of the central nervous system (CNS) currently includes metastatic carcinomas, melanomas, choriocarcinomas, oligodendrogliomas, and glioblastomas. Here we present the clinical, radiological, pathological, and molecular genetic features of six cases of PCNSL associated with intratumoral hemorrhage. The median age of patients was 75 years, with male predominance. While conventional PCNSLs were associated with low cerebral blood volume (CBV), perfusion magnetic resonance imaging (MRI) revealed elevated CBV in three cases, consistent with vascular proliferation. All six cases were diagnosed pathologically as having diffuse large B-cell lymphoma (DLBCL) with a non-germinal center B-cell-like (non-GCB) phenotype; marked histiocytic infiltrates and abundant non-neoplastic T-cells were observed in most cases. Expression of vascular endothelial growth factor and CD105 in the lymphoma cells and the small vessels, respectively, suggested angiogenesis within the neoplasms. Neoplastic cells were immunohistochemically negative for programmed cell death ligand 1 (PD-L1), while immune cells in the microenvironment were positive for PD-L1. Mutations in the MYD88 gene (MYD88) (L265P) and the CD79B gene (CD79B) were detected in five and one case, respectively. As therapeutic modalities used for PCNSLs differ from those that target conventional hemorrhagic neoplasms, full tissue diagnoses of all hemorrhagic CNS tumors are clearly warranted.

Tumor volume and the dural tail sign enable the differentiation of intracranial solitary fibrous tumor/hemangiopericytoma from high-grade meningioma

OBJECTIVES

Intracranial solitary fibrous tumor/hemangiopericytoma (SFT/HPC) is a rare mesenchymal neoplasm with imaging features mimicking high-grade meningioma (HGM) and can easily be misdiagnosed. We sought to determine the value of routine preoperative data in differentiating these tumors.

PATIENTS AND METHODS

Patients with confirmed SFT/HPC or HGM between January 2012 and June 2020 were identified. A total of 28 preoperative variables (including age, sex, tumor location, tumor volume, 10 traditional MRI features, and 14 peripheral blood indices) were collected for each patient. The top features were selected sequentially based on the least absolute shrinkage and selection operator (LASSO) and support vector machines-recursive feature elimination (SVM-RFE) methods. Differentiation and calibration of the classifiers were assessed by receiver operating characteristic (ROC) curves and calibration curves, respectively. Nomograms were constructed based on multivariate analysis.

RESULTS

A total of 127 patients, including 29 with SFT/HPC and 98 with HGM, were analyzed. Three features were first selected using the LASSO and SVM-RFE methods, and corresponding models were developed. Although the area under the curve (AUC) of model 1 was the highest, a comprehensive analysis suggested the superiority of model 2, which consisted only of the features tumor volume (TV) and dural tail sign (DTS) (AUC: 0.942, sensitivity: 93.10%, p-value of H-L test: 0.734, Brier score: 0.07). A risk score formula and a nomogram were constructed.

CONCLUSIONS

TV can be used to effectively identify SFT/HPC and HGM, whereas adding DTS can improve the overall prediction accuracy. As these two variables are routinely available and are easy for clinicians to master, they can provide a powerful reference for clinical decision-making.

Management of meningeal solitary fibrous tumors/hemangiopericytoma; surgery alone or surgery plus postoperative radiotherapy?

INTRODUCTION

A meningeal solitary fibrous tumor (SFT), also called hemangiopericytoma, is a rare mesenchymal malignancy. Due to anatomic constrains, even after macroscopic complete surgery with curative intent, the local relapse risk is still relatively high, thus increasing the risk of dedifferentiation and metastatic spread. This study aims to better define the role of postoperative radiotherapy (RT) in meningeal SFTs.

PATIENTS AND METHODS

A retrospective study was performed across seven sarcoma centers. Clinical information was retrieved from all adult patients with meningeal primary localized SFT treated between 1990 and 2018 with surgery alone (S) compared to those that also received postoperative RT (S + RT). Differences in treatment characteristics between subgroups were tested using independent samples t-test for continuous variables and chi-square tests for proportions. Local control (LC) and overall survival (OS) rates were calculated as time from start of treatment until progression or death from any cause. LC and OS in groups receiving S or S + RT were compared using Kaplan-Meier survival curves.

RESULTS

Among a total of 48 patients, 7 (15%) underwent S and 41 (85%) underwent S + RT. Median FU was 65 months. LC was significantly associated with treatment. LC after S at 60 months was 60% versus 90% after S + RT (p = 0.052). Furthermore, R1 resection status was significantly associated with worse LC (HR 4.08, p = 0.038). OS was predominantly associated with the mitotic count (HR 3.10, p = 0.011).

CONCLUSION

This retrospective study, investigating postoperative RT in primary localized meningeal SFT patients, suggests that combining RT to surgery in the management of this patient population may reduce the risk for local failures.

Hemangiopericytoma: Incidence, Treatment, and Prognosis Analysis Based on SEER Database

Background

Hemangiopericytomas are rare tumors derived from pericytes surrounding the blood vessels. The clinicopathological characteristics and prognosis of hemangiopericytoma patients remain mostly unknown. In this retrospective cohort study, we assessed the clinicopathological characteristics of hemangiopericytoma patients, as well as the clinical usefulness of different treatment modalities. Material and Methods. We collected the clinicopathological data (between 1975 and 2016) of hemangiopericytoma and hemangioendothelioma patients from the Surveillance, Epidemiology, and End Results (SEER) database. Incidence, treatment, and patient prognosis were assessed.

Results

Data from 1474 patients were analyzed in our study cohort (hemangiopericytoma: n = 1243; hemangioendothelioma: n = 231). The incidence of hemangiopericytoma in 2016 was 0.060 per 100,000 individuals. The overall survival (OS) and cancer-specific survival (CSS) did not differ between patients with hemangioendothelioma and those with hemangiopericytoma (P = 0.721, P = 0.544). The tumor grade had no effect on the OS of hemangiopericytoma patients. Multivariate analysis revealed the clinical usefulness of surgery in hemangiopericytoma patients (HR = 0.15, 95% confidence interval: 0.05-0.41, P < 0.001). In contrast, radiotherapy did not improve OS (P = 0.497) or CSS (P = 0.584), and chemotherapy worsened patient survival (P < 0.001). Additionally, the combination of surgery and radiotherapy had a similar effect with surgery alone on hemangiopericytoma patient survival (OS: P = 0.900; CSS: P = 0.156). Surgery plus chemotherapy provided a worse clinical benefit than surgery alone (P < 0.001).

Conclusions

Our findings suggested that hemangiopericytoma had a similar prognosis with hemangioendothelioma. Surgery was the only effective treatment that provided survival benefits in hemangiopericytoma patients, while the clinical usefulness of adjuvant chemotherapy or radiotherapy was limited.

A Case of Intracranial Solitary Fibrous Tumor/Hemangiopericytoma Repeatedly Misdiagnosed as Hypertensive Intracerebral Hemorrhage

Because solitary fibrous tumor (SFT) and hemangiopericytoma (HPC) contain identical genetic abnormalities, the World Health Organization coined the term SFT/HPC to describe these lesions. Here, we present a rare case of SFT/HPC in a 40-year-old man with massive repeated intracranial hemorrhage (ICH) in right medial temporal lobe. ICHs from a SFT/HPC were repeatedly misdiagnosed as hypertensive ICH by several departments and hospitals over approximately eight months, and the patient underwent inappropriate treatments. The amount of repeated ICH accompanying the tumor has increased significantly compared to the first ICH, which may suggest rapid tumor growth. To avoid misdiagnosis and inappropriate treatment, surgeons should carefully examine all past and current patient-related radiological images and medical records before considering surgery.