Clinical outcomes of intracranial solitary fibrous tumor and hemangiopericytoma: analysis according to the 2016 WHO classification of central nervous system tumors

Efficacy and toxicity of photon, proton, and carbon ion radiotherapy in the treatment of intracranial solitary fibrous tumor/hemangiopericytoma

BACKGROUND

Solitary fibrous tumors (SFT) of the central nervous system are rare and treatment options are not well established. The aim of this study was to evaluate the clinical outcomes of radiotherapy (RT) and re-radiotherapy (re-RT) for de novo intracranial SFT and recurrent intracranial SFT.

METHODS

This retrospective study analyzed efficacy and toxicity of different RT modalities in patients who received radiotherapy (RT) for intracranial SFT at Heidelberg University Hospital between 2000 and 2020 following initial surgery after de novo diagnosis ("primary group"). We further analyzed the patients of this cohort who suffered from tumor recurrence and received re-RT at our institution ("re-irradiation (re-RT) group"). Median follow-up period was 54.0 months (0-282) in the primary group and 20.5 months (0-72) in the re-RT group. RT modalities included 3D-conformal RT (3D-CRT), intensity-modulated RT (IMRT), stereotactic radiosurgery (SRS), proton RT, and carbon-ion RT (C12-RT). Response rates were analyzed according to RECIST 1.1 criteria.

RESULTS

While the primary group consisted of 34 patients (f: 16; m:18), the re-RT group included 12 patients (f: 9; m: 3). Overall response rate (ORR) for the primary group was 38.3% (N = 11), with 32.4% (N = 11) complete remissions (CR) and 5.9% (N = 2) partial remissions (PR). Stable disease (SD) was confirmed in 5.9% (N = 2), while 41.2% (N = 14) experienced progressive disease (PD). 14% (N = 5) were lost to follow up. The re-RT group had 25.0% CR and 17.0% PR with 58.0% PD. The 1-, 3-, and 5-year progression-free survival rates were 100%, 96%, and 86%, respectively, in the primary group, and 81%, 14%, and 14%, respectively, in the re-RT group. Particle irradiation (N = 11) was associated with a lower likelihood of developing a recurrence in the primary setting than photon therapy (N = 18) (OR = 0.038; p = 0.002), as well as doses ≥ 60.0 Gy (N = 15) versus < 60.0 Gy (N = 14) (OR = 0.145; p = 0.027). Risk for tumor recurrence was higher for women than for men (OR = 8.07; p = 0.014) with men having a median PFS of 136.3 months, compared to women with 66.2 months.

CONCLUSION

The data suggests RT as an effective treatment option for intracranial SFT, with high LPFS and PFS rates. Radiation doses ≥ 60 Gy could be associated with lower tumor recurrence. Particle therapy may be associated with a lower risk of recurrence in the primary setting, likely due to the feasibility of higher RT-dose application.

Developing a Nomogram to Stratify Intracranial Solitary Fibrous Tumor Recurrence

RATIONALE AND OBJECTIVES

To develop a nomogram to stratify tumor recurrence (TR) in intracranial solitary fibrous tumors (ISFTs) based on the clinical, radiological, and pathological features.

MATERIALS AND METHODS

A total of 215 patients from Beijing Tiantan Hospital, Capital Medical University and 48 patients from Lanzhou University Second Hospital, diagnosed with ISFT based on histopathological findings, were included. The patients were randomly divided into training and test cohorts at a ratio of 8:2. Information regarding clinical, radiological, and histopathological features, and the clinical outcomes was retrospectively analyzed. Univariate and multivariate analyses were performed using the Cox proportional hazard model for TR in the training cohort. A nomogram incorporating the independent risk factors was developed in the training cohort and validated in the test cohort. Its predictive performance was analyzed using the Harrell C-index. Decision curve analysis (DCA) was used to evaluate the net clinical benefit.

RESULTS

The Harrell C-indices for TR at 3 and 5 years were 0.845 (0.578-0.944) and 0.807 (0.612-0.901) for the test cohort, respectively. In the test cohort, the nomogram provided a net clinical benefit in the DCA over the TR scheme or non-TR scheme. Although postoperative radiotherapy (PORT) was useful for TR prevention, high doses (≥46 Gy) were not superior to lower doses in prolonging the progression-free survival.

CONCLUSION

The nomogram obtained in our study had a good predictive performance and could be used for ISFT patients.

Meningeal Solitary Fibrous Tumor: A Single-Center Retrospective Cohort Study

Background

Meningeal solitary fibrous tumors (SFTs) are rare, malignant, mesenchymal tumors of the central nervous system. While surgical gross total resection is widely accepted as a positive prognostic factor for local control (LC), the role of postoperative radiotherapy (PORT) remains controversial. We sought to report our institutional experience with a particular focus on outcomes after PORT.

Materials and Methods

In this single-center, retrospective cohort study, 20 patients with the primary diagnosis of histopathologically confirmed meningeal SFT were analyzed. Data on patient characteristics, imaging, treatment modalities, histopathology, and oncological outcomes were collected. LC and overall survival (OS) were assessed using the Kaplan-Meier estimator.

Results

The median follow-up time was 95.8 months. After surgery only, 9 out of 11 patients (81.8%) developed a local recurrence while, after surgery and PORT, 3 out of 9 patients (33.33%) showed local failure. The 5- and 10-year LC rates were 50.5% and 40.4% in the surgery-only group and 80% at both time points in the surgery with the PORT group. In the surgery-only group, 4 out of 11 patients (36.4%) died, and 4 out of 9 patients (44.4%) died in the surgery and PORT group. OS rates after 5 and 10 years were 88.9% and 66.7% in the surgery-only group and 88.9% and 76.2% in the surgery with PORT group.

Conclusions

Our findings suggest that PORT may improve LC in patients with meningeal SFT. The low incidence of meningeal SFT impedes prospective studies and requires further international collaborative efforts to exploit retrospective datasets and molecular analysis to improve patient outcomes.

Postoperative stereotactic radiosurgery for intracranial solitary fibrous tumors: systematic review and pooled quantitative analysis

BACKGROUND

Intracranial solitary fibrous tumors (SFTs), formerly hemangiopericytomas (HPCs), are rare, aggressive dural-based mesenchymal tumors. While adjuvant radiation therapy has been suggested to improve local tumor control (LTC), especially after subtotal resection, the role of postoperative stereotactic radiosurgery (SRS) and the optimal SRS dosing strategy remain poorly defined.

METHODS

PubMed, EMBASE, and Web of Science were systematically searched according to PRISMA guidelines for studies describing postoperative SRS for intracranial SFTs. The search strategy was defined in the authors' PROSPERO protocol (CRD42023454258).

RESULTS

15 studies were included describing 293 patients harboring 476 intracranial residual or recurrent SFTs treated with postoperative SRS. At a mean follow-up of 21-77 months, LTC rate after SRS was 46.4-93% with a mean margin SRS dose of 13.5-21.7 Gy, mean maximum dose of 27-39.6 Gy, and mean isodose at the 42.5-77% line. In pooled analysis of individual tumor outcomes, 18.7% of SFTs demonstrated a complete SRS response, 31.7% had a partial response, 18.9% remained stable (overall LTC rate of 69.3%), and 30.7% progressed. When studies were stratified by margin dose, a mean margin dose > 15 Gy showed an improvement in LTC rate (74.7% versus 65.7%).

CONCLUSIONS

SRS is a safe and effective treatment for intracranial SFTs. In the setting of measurable disease, our pooled data suggests a potential dose response of improving LTC with increasing SRS margin dose. Our improved understanding of the aggressive biology of SFTs and the tolerated adjuvant SRS parameters supports potentially earlier use of SRS in the postoperative treatment paradigm for intracranial SFTs.

Development of an MRI-Based Comprehensive Model Fusing Clinical, Radiomics and Deep Learning Models for Preoperative Histological Stratification in Intracranial Solitary Fibrous Tumor

BACKGROUND

Accurate preoperative histological stratification (HS) of intracranial solitary fibrous tumors (ISFTs) can help predict patient outcomes and develop personalized treatment plans. However, the role of a comprehensive model based on clinical, radiomics and deep learning (CRDL) features in preoperative HS of ISFT remains unclear.

PURPOSE

To investigate the feasibility of a CRDL model based on magnetic resonance imaging (MRI) in preoperative HS in ISFT.

STUDY TYPE

Retrospective.

POPULATION

Three hundred and ninety-eight patients from Beijing Tiantan Hospital, Capital Medical University (primary training cohort) and 49 patients from Lanzhou University Second Hospital (external validation cohort) with ISFT based on histopathological findings (237 World Health Organization [WHO] tumor grade 1 or 2, and 210 WHO tumor grade 3).

FIELD STRENGTH/SEQUENCE

3.0 T/T1-weighted imaging (T1) by using spin echo sequence, T2-weighted imaging (T2) by using fast spin echo sequence, and T1-weighted contrast-enhanced imaging (T1C) by using two-dimensional fast spin echo sequence.

ASSESSMENT

Area under the receiver operating characteristic curve (AUC) was used to assess the performance of the CRDL model and a clinical model (CM) in preoperative HS in the external validation cohort. The decision curve analysis (DCA) was used to evaluate the clinical net benefit provided by the CRDL model.

STATISTICAL TESTS

Cohen's kappa, intra-/inter-class correlation coefficients (ICCs), Chi-square test, Fisher's exact test, Student's t-test, AUC, DCA, calibration curves, DeLong test. A P value <0.05 was considered statistically significant.

RESULTS

The CRDL model had significantly better discrimination ability than the CM (AUC [95% confidence interval, CI]: 0.895 [0.807-0.912] vs. 0.810 [0.745-0.874], respectively) in the external validation cohort. The CRDL model can provide a clinical net benefit for preoperative HS at a threshold probability >20%.

DATA CONCLUSION

The proposed CRDL model holds promise for preoperative HS in ISFT, which is important for predicting patient outcomes and developing personalized treatment plans.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

A pregnant woman with a giant bilateral parietal hemangiopericytoma underwent multiple surgeries and radiotherapy: a case report and literature review

Intracranial hemangiopericytoma is a rare invasive tumor originating from mesenchymal fibroblasts and is prone to local recurrence and distant metastasis. This study reports a case of a 27-year-old woman who presented with severe headache, nausea and vomiting for two weeks at thirty-three weeks of gestation. Cranial magnetic resonance imaging (MRI) demonstrated a giant lesion in the bilateral parietal lobe with a size of 5.12x9.19x6.03 cm and severe edema in the surrounding brain tissue. The patient underwent four operations and 3 gamma knife radiosurgery procedures and is recovering well now. The histopathology findings showed hemangiopericytoma and STAT6 and CD34 positivity after the first and second surgeries. Because of tumor progression, the patient received gamma knife radiosurgery at 1, 3, and 4 years after the first operation. Total tumor resection was achieved in the fourth surgery. Nevertheless, the patient showed malignant transformation to from low-grade to high-grade hemangiopericytoma.

A rare case of intracranial solitary fibrous tumor that is still alive after multiple surgical resections: a case report and review of the literature

A Solitary Fibrous Tumor (SFT) is a rare, aggressive, and metastasis- and recurrence- prone mesenchymal tumor. In this case report and review, we describe a rare instance of intracranial SFT, discovered for the first time. It was discovered in 2008 and following total surgical removal, the pathology was categorized as hemangiopericytoma cell tumor (HPC) at the time by WHO tumor criteria. An imaging review 8 months after surgery revealed a tumor recurrence: combined radiation and gamma-knife therapy was continued throughout this time. The tumor did not metastasis until June 2018 when it presented in the pancreas with ruptured bleeding and a postoperative pathology was suggestive of SFT. Fortunately, the patient is still alive nearly 3 years after the 2020 surgery, after staged surgical resection and combined multimedia therapy, with no imaging or clinical evidence of a recurrent intracranial primary lesions. To our knowledge, there is no previous record of using a combined treatment modality for Intracranial Solitary Fibrous Tumor (ISFT). Combined with an account of the patient's experience, we empirically describe a combined approach with a preference for gross-total resection (GTR), supplemented by multimodal assistance with stereotactic (radiotherapy), gamma knife (GK), molecular targeting, and immunization for patients admitted acutely, with accurate preoperative identification and aggressive management after intraoperative case response to maximize treatment of recurrent ISFT and improve prognosis. We recommend multimodal management for SFT with prolonged-term recurrence and metastases, both for the control benefits of GTR, RT, or GK for local recurrence and for the positive prognosis of targeted and immune metastases.

Impact of extent of resection and postoperative radiotherapy on survival outcomes in intracranial solitary fibrous tumors: a systematic review and meta-analysis

The knowledge of optimal treatments for patients with intracranial solitary fibrous tumor (SFT) is limited, with inconclusive results from previous studies. In this study, we conducted a meta-analysis of relevant studies to identify the prognostic impact of the extent of resection (EOR) and postoperative radiotherapy (PORT) on survival outcomes of patients with intracranial SFT. We searched the Medline, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) to identify relevant studies published till April 2022. Progression-free survival (PFS) and overall survival (OS) were the outcomes of interest. Differences between two cohorts (gross total resection [GTR] vs. subtotal resection [STR] and PORT vs. surgery only) were estimated by calculating hazard ratios. Twenty-seven studies were selected for the meta-analysis, including data of 1348 patients (GTR, n = 819 vs. STR, n = 381 and PORT, n = 723 vs. surgery only, n = 578). Pooled hazard ratios of PFS (1, 3, 5, and 10 years) and OS (3, 5, and 10 years) revealed that the GTR cohort showed sustained superiority over the STR cohort. In addition, the PORT cohort was superior to the surgery-only cohort with respect to all PFS periods. Although the 10-year OS between the two cohorts was not statistically different, PORT showed significantly better 3- and 5-year OS than surgery only. The study findings suggest that GTR and PORT provide significant benefits for PFS and OS. Aggressive surgical resection of tumors to achieve GTR followed by PORT should be implemented as optimal treatments for all patients with intracranial SFT when feasible.

Intracranial Solitary Fibrous Tumour Management: A French Multicentre Retrospective Study

BACKGROUND

Intracranial solitary fibrous tumour (iSFT) is an exceptional mesenchymal tumour with high recurrence rates. We aimed to analyse the clinical outcomes of newly diagnosed and recurrent iSFTs.

METHODS

We carried out a French retrospective multicentre (n = 16) study of histologically proven iSFT cases. Univariate and multivariate Cox models were used to estimate the prognosis value of the age, location, size, WHO grade, and surgical extent on overall survival (OS), progression-free survival (PFS), and local recurrence-free survival (LRFS).

RESULTS

Eighty-eight patients were included with a median age of 54.5 years. New iSFT cases were treated with gross tumour resection (GTR) (n = 75) or subtotal resection (STR) (n = 9) and postoperative radiotherapy (PORT) (n = 32, 57%). The median follow-up time was 7 years. The median OS, PFS, and LRFS were 13 years, 7 years, and 7 years, respectively. Forty-two patients experienced recurrence. Extracranial metastasis occurred in 16 patients. Median OS and PFS after the first recurrence were 6 years and 15.4 months, respectively. A higher histological grade was a prognosis factor for PFS (p = 0.04) and LRFS (p = 0.03). GTR influenced LRFS (p = 0.03).

CONCLUSION

GTR provided benefits as a first treatment for iSFTs. However, approximately 40% of patients experienced relapse, which remains a challenging state.

Epidemiology and survival of patients with central nervous system solitary fibrous tumors: A population-based analysis

Background

The objective of this study was to determine population-based estimates of the epidemiology and prognosis of central nervous system solitary fibrous tumors (cSFTs).

Methods

We extracted the data of patients diagnosed with cSFTs between 2004 and 2018 from the Surveillance, Epidemiology, and End Results database. We analyzed the distribution of patients according to their demographic and clinical characteristics. Binary logistic regression analysis was performed to predict which patients would be diagnosed with malignant cSFT. Possible prognostic indicators were analyzed by multivariable Cox proportional hazards models.

Results

A total of 650 cases were included. The majority of patients were diagnosed at 50-59 years old, and the median age at diagnosis was 55 years. A total of 13.4% of the tumors were located in the spinal canal, and 24% of the tumors were benign. Most of the tumors were larger than 3 cm, but distant metastasis was rare. Tumor resection was the first choice of treatment for these patients, and total resection was achieved in 51.1%. Radiation therapy after surgery was also administered to 42.3% of the patients. The median survival was 57 months. Intracranial tumors and tumors with distant metastasis tended to be malignant. The results of the log-rank test showed that the patients who underwent total resection had better overall survival (OS), but the effect of radiation therapy after surgery was not significant.

Conclusion

cSFT is a rare and aggressive type of tumor. Tumor resection is the first choice for treatment, and radiation therapy after surgery does not improve OS. Patients older than 60 years of age who are diagnosed with intracranial tumors, malignant tumors and distant metastasis have worse OS outcomes than their counterparts.

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.

Rare magnetic resonance imaging findings of intracranial solitary fibrous tumor: A case report

RATIONALE

Solitary fibrous tumor (SFT) is a rare mesenchymal spindle cell tumor. SFT in the central nervous system (CNS) is rare. This case reports rare magnetic resonance imaging (MRI) findings of intracranial SFT (ISFT).

PATIENT CONCERNS

We report a 47-year-old female patient who was found to have weakness in her right limb with walking instability 2 months before the visit.

DIAGNOSES

Based on imaging, the provisional diagnosis was meningioma. Postsurgical histopathological diagnosis confirmed World Health Organization (WHO) grade I SFT/hemangiopericytoma (HPC).

INTERVENTIONS

The lesion was totally excised. The patient improved remarkably after the operation, without any signs of associated limb movement disorder.

OUTCOMES

No local recurrence or metastases were observed in the follow-up 3 months after the surgery.

LESSONS

Intracranial SFT is a rare mesenchymal tumor. Due to different tumor components, imaging manifestations are diverse and lack of characteristics, so preoperative diagnosis is challenging. Our case provides a rare ISFT with significantly decreased signal intensity in T2 weighted images (T2WI), which is an important supplement to the rare imaging findings of intracranial SFT.

Intracranial solitary fibrous tumor/hemangiopericytoma: Role and choice of postoperative radiotherapy techniques

Background

Intracranial solitary fibrous tumor/hemangiopericytoma (SFT/HPC) is a novel rare disease after the 2016 WHO reclassification. Surgery is the main treatment. Postoperative adjuvant radiotherapy is often used, but the effects of different radiotherapy techniques are still unclear. The purpose of this study was to analyze the effects of postoperative radiotherapy (PORT) and different radiotherapy methods on the efficacy of patients with intracranial SFT/HPC.

Materials and methods

We retrospectively analyzed 42 patients with intracranial SFT/HPC who underwent surgical treatment from 2008 to 2022, 20 of whom were treated with postoperative intensity-modulated radiotherapy (IMRT) and 22 with postoperative stereotactic radiosurgery (SRS). The Kaplan–Meier method was used to analyze the disease-free survival (DFS) of all the 42 patients receiving postoperative radiotherapy and the time to progression (TTP) of 22 of these patients experiencing recurrence. A multivariate Cox proportional hazards model was used to detect prognostic factors of survival.

Results

In the analysis of PORT patients, the median DFS was 8.33 years for PORT IMRT patients and 3.04 years for PORT SRS patients. The 10-year DFS incidence was 46.0% in the PORT IMRT group and 27.5% in the SRS group. Among the 22 patients who relapsed, the median TTP of other patients was 1.25 years, of which 3 received radiotherapy alone and 1 received symptomatic treatment, while the median TTP of surgical and surgical combined with radiotheray patients were 1.83 and 2.49 years, respectively (p=0.035).

Conclusion

PORT IMRT could prolong DFS compared with PORT SRS. It indicated that PORT IMRT radiotherapy technology was a feasible option for SFT/HPC. Moreover, TTP results of relapsed patients showed that, surgery and surgery combined with radiotherapy treatments have no significant difference on TTP in relapsed patients, but both of them were better than other treatments.

Delayed pulmonary metastasis and recurrence of intracranial malignant solitary fibrous tumor/hemangiopericytoma: Case report and literature review

Solitary fibrous tumors/hemangiopericytomas (SFTs/HPCs) are intracranial spindle cell tumors that originate from interstitial tissue. SFTs/HPCs that are primary malignant intracranial tumors are exceedingly uncommon. A case of intracranial malignant SFT/HPC that originated intracranially and spread to the pulmonary region is described herein. Furthermore, the specimens from two surgical resections obtained when the patient had undergone two prior procedures for intracranial ‘meningiomas’ were also reviewed. The results of the lung biopsy matched the morphologic appearance of the intracranial tumor. The patient died ~2 years after the chest pain started. In addition, the literature was reviewed. According to previous studies, STAT6 expression was positive in 100% of SFTs/HPCs and radiologic characteristics assisted in determining the tumor pathology and grade. Surgical management has been the mainstay treatment for SFTs. In cases of incomplete resection, adjuvant radiotherapy is effective and rigorous follow-up is required to monitor for recurrence.

Apparent diffusion coefficient histogram analysis to preoperative evaluate intracranial solitary fibrous tumor: Relationship to Ki-67 proliferation index

PURPOSE

To explore the value of apparent diffusion coefficient (ADC) histogram analysis in preoperative evaluating intracranial solitary fibrous tumor (SFT) and further investigate the relationship between ADC histogram parameters and the Ki-67 proliferation index.

METHODS

From January 2014 to March 2022, 37 patients with intracranial SFT (grade 2, n = 20; grade 3, n = 17) who underwent preoperative diffusion-weighted imaging were enrolled in this study. For each tumor, nine histogram parameters were automatically extracted and selected using MaZda software based on the axial ADC maps of the whole tumor, including mean, variance, skewness, kurtosis, as well as the 1st, 10th, 50th, 90th, and 99th percentile ADC (Perc.01, Perc.10, Perc.50, Perc.90, Perc.99). Differences in ADC histogram parameters between grade 2 and 3 intracranial SFT were compared. Receiver operating characteristic (ROC) curves were drawn to determine the diagnostic performance, and Pearson's correlation coefficient was used to investigate the relationship between these parameters and the Ki-67 proliferation index.

RESULTS

The mean, Perc.01, Perc.10, Perc.50, Perc.90, and Perc.99 were significantly lower in grade 3 than in grade 2 intracranial SFT (all P < 0.05). ROC analysis showed that these parameters can effectively distinguish between the two groups, with Perc.01 generating the best differentiation performance. Significant negative correlations were also observed between these parameters and the Ki-67 proliferation index (r = -0.436 ~ -0.522, all P < 0.05). However, there was no significant difference in variance, skewness, or kurtosis between the two groups (all P > 0.05).

CONCLUSIONS

ADC histogram analysis enables effective preoperative distinction of grade 2 and grade 3 intracranial SFT.

Cerebral Hemangiopericytoma Manifesting as Epilepsia Partialis Continua: A Case Report

Cerebral hemangiopericytomas are very rare mesenchymal tumours arising from pericytes surrounding the blood vessels in the brain. Most patients present with headaches, focal neurological findings and focal seizures with or without generalisation. Our patient chiefly complained of an uncontrollable movement of her right hand that was initially fleeting but later became continuous. Her symptoms were initially described as tremors. We found an intracranial tumour as a cause of her symptoms, suspected the tumour to be a meningioma and performed surgical extirpation which resulted in symptom resolution. Histopathology and immunohistochemistry of the excised mass revealed that the tumour was hemangiopericytoma. The patient is being closely monitored for recurrences and metastasis. Hemangiopericytomas are very rare and they rarely result in the abnormal movements of epilepsia partialis continua. Differentiation of the abnormal movements of epilepsia partialis continua from tremors is very important as is the differentiation of the tumour from meningioma.

Keywords

case reports; epilepsia partialis continua; hemangiopericytoma; solitary fibrous tumors.

Clinical outcomes in central nervous system solitary-fibrous tumor/hemangiopericytoma: a STROBE-compliant single-center analysis

Background

Solitary fibrous tumor (SFT) and hemangiopericytoma (HPC) are rare mesenchymal tumors in the central nervous system with a high tendency to relapse, having a significant impact on quality of life (QoL). Due to the rarity of intracranial SFT/HPC, the prognostic factors and optimal treatment remain to be elucidated. Meanwhile, quality of life in patients with intracranial SFT/HPC is seldomly concerned. Thus, we aim to survey about the quality of life and underline some aspects demanding concern in intracranial SFT/HPC treatment through summarizing our case series in recent ten years.

Methods

Patients with intracranial SFT/HPC who underwent surgical resection from January 2009 to June 2019 were included in the study. Clinical features, such as age, gender, and resection extent, were collected. The EuroQol Five Dimensions Questionnaire (EQ-5D) was used to assess the patients’ quality of life (QoL). Prognosis factors related to progression-free survival (PFS) and overall survival (OS) were also evaluated.

Results

Thirty-six patients with a mean follow-up period of 61.6 months (range 13–123 months) were included in this study. Sixteen (44.4%) patients achieved gross total resection (GTR). Fourteen patients (38.9%) with tumor progression experienced adjuvant radiotherapy (11.1%) or Gamma Knife surgery (GKS, 27.8%). According to the 2016 WHO classification, there were 6 (16.7%) grade I SFT/HPC, 11 (30.5%) grade II SFT/HPC, and 19 (52.8%) grade III SFT/HPC. The PFS and OS were 29 months (range 4–96 months) and 38 months (range 4–125 months). The median EQ5D-3 L tariff with or without progression was 0.617 (95% CI 0.470–0.756) and 0.939 (95% CI 0.772–0.977) respectively. Gross total resection (GTR, p = 0.024) and grade I SFT/HPC (p = 0.017) were significantly associated with longer PFS. In multivariate analysis, GTR (HR 0.378, 95% CI 0.154–0.927) and adjuvant therapy (HR 0.336, 95% CI 0.118–0.956) result in significantly longer PFS in patients with SFT/HPC.

Conclusions

Patients underwent GTR and adjuvant therapy had longer PFS. Similarly, patients with lower WHO grade had relatively longer PFS. Therefore, GTR is advocated for the treatment of SFT/HPC. And adjuvant therapy such as GKS could be an alternative treatment for patients who underwent STR or with tumor progression. Further, the QoL decreased in patients with tumor progression and metastasis, and more attention is demanded to the QoL of intracranial SFT/HPC patients.

Solitary Fibrous Tumor of the Spine: Imaging Grading Diagnosis and Prognosis

OBJECTIVE

This study aimed to investigate the imaging features and prognosis of spinal solitary fibrous tumors (SFTs) of different pathological grades.

METHODS

The clinical features, computed tomography and magnetic resonance (MR) images, and follow-up data of 23 patients with SFTs were reviewed. The patients were divided into 3 groups according to their pathological manifestations: grade 1 (n = 3), grade 2 (n = 14), and grade 3 (n = 6). The following imaging features were recorded: location, computed tomography density/MR intensity, enhancement pattern, dural tail sign, adjacent bone remodeling, lobulation, and tumor size. The immunohistochemical (Ki-67/MIB-1) levels were also investigated. All parameters were statistically analyzed between grade 2 and 3 tumors.

RESULTS

The Ki-67/MIB-1 index was markedly higher in grade 3 tumors than in grade 2 tumors (P < 0.001). All grade 1 lesions appeared hypointense on T2-weighted image, whereas grade 2 and 3 lesions appeared isointense or mildly hyperintense. There were significant differences in enhancement type and osteolytic bony destruction between grade 2 and 3 tumors (P < 0.05). However, no marked differences were found in the distribution of age, sex, location, MR signal, degree of enhancement, compressive bony absorption, dural tail sign, or maximum vertical/traverse diameter ratio. Malignant progression occurred less frequently in patients with grade 2 tumors than in those with grade 3 tumors, but the difference was not statistically significant.

CONCLUSIONS

Different grades of spinal SFTs have different degrees of proliferation and imaging features, especially grade 3 tumors, which show a heterogeneous enhancement pattern, osteolytic bony destruction, and a higher possibility of recurrence and metastasis.

Deep Learning Model for Intracranial Hemangiopericytoma and Meningioma Classification

Background

Intracranial hemangiopericytoma/solitary fibrous tumor (SFT/HPC) is a rare type of neoplasm containing malignancies of infiltration, peritumoral edema, bleeding, or bone destruction. However, SFT/HPC has similar radiological characteristics as meningioma, which had different clinical managements and outcomes. This study aims to discriminate SFT/HPC and meningioma via deep learning approaches based on routine preoperative MRI.

Methods

We enrolled 236 patients with histopathological diagnosis of SFT/HPC (n = 144) and meningioma (n = 122) from 2010 to 2020 in Xiangya Hospital. Radiological features were extracted manually, and a radiological diagnostic model was applied for classification. And a deep learning pretrained model ResNet-50 was adapted to train T1-contrast images for predicting tumor class. Deep learning model attention mechanism was visualized by class activation maps.

Results

Our study reports that SFT/HPC was found to have more invasion to venous sinus (p = 0.001), more cystic components (p < 0.001), and more heterogeneous enhancement patterns (p < 0.001). Deep learning model achieved a high classification accuracy of 0.889 with receiver-operating characteristic curve area under the curve (AUC) of 0.91 in the validation set. Feature maps showed distinct clustering of SFT/HPC and meningioma in the training and test cohorts, respectively. And the attention of the deep learning model mainly focused on the tumor bulks that represented the solid texture features of both tumors for discrimination.

Long-term extracranial metastatic relapse of an intraventricular solitary fibrous tumor: a case report

Solitary fibrous tumors (SFTs), an uncommon subtype of soft tissue sarcomas mesenchymal, are frequently diagnosed in the intra-thoracic region. Distant metastasis is detected in 10-40% of SFT patients with a predilection site to the lungs; nevertheless, these can occur rarely in the liver, brain, and bones. This entity was also reported in the abdomen, trunk, head, and neck, extremities but also, in the central nervous system (CNS). In the latter form of SFTs, the meninges were mostly affected while only a few cases were reported in the intraventricular and intraparenchymal region with distinct clinical and behavioral characteristics. In this article, we report the rare case of a relapsing intraventricular SFT with secondary extra-cranial metastases to the bones and soft tissues after 11 years of initial diagnosis, with focus on the available data in the literature on CNS SFTs.

Intradural Extramedullary Solitary Fibrous Tumor of the Thoracic Spinal Cord

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

Rare hypervascular pancreatic tumors diagnosed as asynchronous metastases of central nervous system solitary fibrous tumor/hemangiopericytoma

A 70-year-old woman was referred to our hospital for asymptomatic pancreatic tumors. She had a history of hemagiopericytoma (HPC) about 20 years ago, and no apparent recurrence has been observed. Contrast-enhanced computed tomography revealed two hypervascular tumors in the head and uncinate process of the pancreas, and no obvious neoplastic lesions were found in other organs. Endoscopic ultrasound guided fine-needle aspiration cytology was performed and histopathology showed that spindle-shaped tumor cells were arranged in a hemangiopericytoma-like pattern and positive for STAT6, which was a characteristic feature of solitary fibrous tumors (SFTs). Immunohistochemical staining for surgical pathology specimens from past HPC showed positive expression of STAT6, which was Grade 2 central nervous system solitary fibrous tumor/hemagiopericytoma (CNS SFT/HPC) according to the current WHO classification. From these findings, the pancreatic tumors were preoperatively diagnosed as pancreatic metastases of CNS SFT/HPC. She underwent pancreaticoduodenectomy. Histopathological examination of the surgically resected specimen proved that the both pancreatic tumors were SFT/HPC. Thus, pancreatic tumors were finally diagnosed as asynchronous pancreatic metastases from CNS SFT/HPC. Although extremely rare, metastatic pancreatic tumors derived from SFT/HPC should be considered as a differential diagnosis for hypervascular pancreatic tumors, especially when having a past history of brain tumors.

Intracranial solitary fibrous tumor/hemangiopericytoma: tumor reclassification and assessment of treatment outcome via the 2016 WHO classification

PURPOSE

As per the 2016 World Health Organization (WHO) guidelines on the classification of central nervous system tumors, solitary fibrous tumors (SFTs) and hemangiopericytomas (HPCs) constitute a single disease entity, known as SFT/HPC. This study provides a clinical analysis of these tumors and describes the treatment outcomes of SFT/HPCs.

METHODS

This retrospective study included 76 patients with histopathologically proven SFT/HPC. Reclassification according to the 2016 WHO guideline was done for patients who were diagnosed with SFT or HPC based on the 2007 WHO classification. Recurrence-free survival (RFS) and overall survival (OS) were evaluated for all patients and subgroups.

RESULTS

The median follow-up period was 77.9 months. The median RFS and OS were 126.5 and 136.8 months, respectively. The 1-, 5-, 10-, and 15-year RFS rates were 93%, 72%, 40%, and 40%, respectively. The 1-, 5-, 10- and 15-year OS rates were 97%, 89%, 54%, and 35%, respectively. In multivariable analyses, stereotactic radiosurgery (SRS; p = 0.009, hazard ratio [HR] 6.986), female sex (p = 0.023, HR 1.76), and age over 45 (p = 0.037, HR 2.74) were associated with shorter RFS. Patients who underwent SRS as initial treatment had a shorter OS than that of patients who underwent primary resection (p < 0.001, HR 12.86).

CONCLUSIONS

High-grade tumors tended to have worse OS and occur extracranial metastases earlier than low-grade tumors. The median RFS was not different between grade II and III tumors. Male sex, younger age, and GTR were associated with a better RFS. A history of SRS before tumor resection was associated with a shorter RFS and OS.

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.

Solitary fibrous tumor of thoracic cavity, extra-thoracic sites and central nervous system: Clinicopathologic features and association with local recurrence and metastasis

Published risk stratification models of solitary fibrous tumor (SFT) have been associated with distant metastases outside the central nervous system (CNS), but have not been studied for tumors occurring in the CNS. In a retrospective review, we identified 72 cases of solitary fibrous tumor or hemangiopericytoma (HPC) diagnosed between January 2011 and December 2020 at our institution. The tumors involved the central nervous system (N = 17), thoracic cavity (N = 28), and extrathoracic sites (N = 27). The risk of local recurrence, distant metastasis, or death at 5 years was 57% (95% CI 23%, 76%) in the CNS, 24% (95% CI 2%, 41%) in the thoracic cavity, and 13% (95% CI 0%, 25%) in extrathoracic sites. By contrast, the risk of distant metastasis or death at 5 years was 13% (95% CI 0%, 29%) in CNS primaries, 5% (95% CI 0%, 14%) in thoracic primaries, and 14% (95% CI 0%, 27%) in extrathoracic primaries. Using the published 3- and 4-variable risk stratification models by Demicco et al., we retrospectively assessed our cases for risk of local recurrence, distant metastasis, and death. For tumors outside the CNS, we show that three- and four-variable risk stratification models were associated with recurrence-free survival in addition to the previously known association with distant metastasis (all P < 0.05). In contrast, inside the CNS, we show that neither risk model is a significantly associated with clinical behavior, and that WHO grade is likely the best available prognostic tool, though none of the differences were significant. The lack of significant differences can be likely explained by the younger median age (47 years vs 61 years) and smaller median tumor size (3.5 cm vs 5.6 cm), downgrading the risk stratification scores in CNS compared to non-CNS primaries. In conclusion, existing risk stratification models of SFT are not associated with clinical behavior for tumors arising inside the CNS, but are associated with local recurrence in addition to distant metastasis outside the CNS.

A Footprint-Like Intracranial Solitary Fibrous Tumor/Hemangiopericytoma With Extracranial Extension and Acute Intratumoral Hemorrhage

BACKGROUND

Intracranial solitary fibrous tumors/hemangiopericytomas (ISFTs/HPCs) are extremely rare spindle-cell tumors that are mostly benign and derived from mesenchymal tissue. Extracranial metastasis and intratumoral hemorrhage are considered to be special manifestations of malignant tumors, of which extracranial metastases of ISFTs/HPCs have been reported, while tumor hemorrhage has rarely been described. Here, the authors present an interesting case of ISFTs/HPCs with acute intratumoral hemorrhage.

CLINICAL PRESENTATION

A 72-year-old woman underwent brain magnetic resonance imaging (MRI) for recurrent headaches and nausea. The MRI scan showed a footprint-like space-occupying lesion in the bilateral parietooccipital lobe. This lesion had multiple cystic components and invaded the superior sagittal sinus, destroying adjacent cranial bones. While waiting for routine surgery, the patient suddenly developed acute tumor bleeding and then underwent emergency surgery. Postoperatively, the diagnosis of ISFT/HPC was confirmed by pathological and immunohistochemical analysis.

DISCUSSIONS AND CONCLUSIONS

The diagnosis of ISFT/HPC mainly depends on pathological and immunohistochemical results. Malignant cases with cystic necrosis may be prone to acute hemorrhage. Early total surgical excision can provide a good clinical prognosis. Adjuvant radiotherapy is an effective supplement to surgical treatment. Metastasis and recurrence require long-term follow-up monitoring.

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.

Salvage carbon ion radiotherapy for recurrent solitary fibrous tumor: A case report and literature review

BACKGROUND

Malignant solitary fibrous tumor (MSFT) arising from the spinal cord is extremely rare and poorly understood mesenchymal neoplasms: only a few MSFT in the spinal canal has been described. We describe the clinical course of the patient with MSFT arising from the thoracic spinal cord.

CASE REPORT

We describe the clinical course of the patient and the radiological and pathological findings of the tumor. The tumor had been resected by microscopic posterior approach and video-assisted thoracic surgery, but local recurrence was observed by MRI at 1-year follow-up period. No metastatic lesion was confirmed. Then, carbon ion radiotherapy (CIRT) was administered to the recurrent lesion. Local suppression has been observed for 40 months after irradiation.

CONCLUSION

Dumbbell-shaped MSFT arising from thoracic spinal cord is a highly unusual presentation. CIRT might be effective for treatment of recurrent tumors.

CAMTA1, a novel antitumor gene, regulates proliferation and the cell cycle in glioma by inhibiting AKT phosphorylation

Identifying biomarkers for the early diagnosis of glioma and elucidating the molecular mechanisms underlying the development of this cancer are of considerable clinical importance. Recently, studies performing microarray profiling of genes to identify distinct gene signatures reported specific subtypes with predictive and prognostic relevance. Thus, we performed deep sequencing on a total of 26 glioma tissue samples to identify the frequently mutated of oncogenes and tumor suppressors in gliomas. A total of 2306 single-nucleotide polymorphisms (SNPs) and 2010 insertion and deletion sites (indels) were found by aligning sequencing information from 26 glioma samples with sequences from the normal human gene database (GRCh37/hg19). GSEA results suggest that an underexpressed gene, calmodulin binding transcription activator 1 (CAMTA1), participates in the cell proliferation and cell cycle regulation of glioma cells. Moreover, overexpression of CAMTA1 in glioma cells notably inhibited cell growth, migration, invasion and cell cycle and enhanced temozolomide (TMZ)-induced cell apoptosis in glioma cells, while CAMTA1 overexpression decreased the ITGA5, ITGB1, p-AKT, p-FAK, and Myc protein levels, suggesting that the signaling pathways of these proteins might be involved in the cellular functions of CAMTA1 in glioma. Moreover, overexpression of CAMTA1 attenuated the growth and tumorigenesis of glioma in vivo. In summary, we identified high-frequency mutant genes in glioma and provided an experimental basis for a novel mechanism by which CAMTA1 may serve as a tumor suppressor in glioma.

Intracranial solitary fibrous tumor/hemangiopericytoma - A case series

Background:

Intracranial solitary fibrous tumor/hemangiopericytoma (HPC) is a rare and aggressive tumor. We conducted this retrospective study to investigate the outcome of patients after treatment, the efficacy of postoperative adjuvant radiotherapy, and the factors not conducive to total resection.

Methods:

We conducted a retrospective review of the medical records of patients harboring fresh intracranial solitary fibrous tumor/HPC treated from January 2009 to December 2019 in our hospital. We reviewed their clinical presentations, radiologic appearances, tumor size and location, extent of resection, estimate intraoperative blood loss, treatment modalities and results, and duration of follow-up.

Results:

There were seven consecutive patients (three males and four females). The ages of the patients at the time of diagnosis ranged from 35 to 77 years (mean: 52.86 years). Five patients (71.43%) got tumor bigger than 5 cm in dimension and only 1 patient (14.29%) underwent gross total tumor resection in the first operation without complication. Five patients (71.43%) underwent postoperative adjuvant radiotherapy. Follow-up period ranged from 4.24 to 123.55 months and the median follow-up period was 91.36 months. Three patients had favorable outcome with Glasgow Outcome Scale (GOS) equal to 4; four patients had unfavorable outcome with GOS equal to 2 or 3. No mortality was happened.

Conclusion:

Gross total tumor resection in the initial surgery is very important to achieve a better outcome. Massive intraoperative bleeding and venous sinus or major vessels adjoining are factors not conducive to total resection. Radiotherapy can be administered as adjuvant therapy for cases showing an aggressive phenotype or not treated with gross total resection.

De-differentiation associated with drop metastasis of a recurrent intracranial solitary fibrous tumor: a case report and literature review

BACKGROUND

Central nervous system is a rare occurring location of solitary fibrous tumors (SFTs). SFTs have a potential for recurrence, which is the leading cause of death in patients with these disease entities. De-differentiation phenomenon combined with cerebrospinal fluid (CSF) dissemination through drop metastasis of STFs from intracranial to intraspinal has only been reported in extremely limited cases.

CASE DESCRIPTION

Herein, we present a case of SFT in a 54-year old male. MRI showed characteristic of mixed high and low signal with 6.3 cm × 6.5 cm × 5.9 cm. After radical surgical resection, the pathology indicated benign SFT. However, MRI re-examination of 22 months later detected local recurrence, concomitant with spreading of intracranial and intraspinal through CSF dissemination. And interestingly, the second pathology found de-differentiation phenomenon and malignance of SFT, in which some areas transformed to rhabdomyosarcoma.

CONCLUSION

This is the first case report of recurrent intracranial SFT de-differentiating to rhabdomyosarcoma concurrent with CSF pathway drop metastasis. Benign intracranial SFTs have the potential of de-differentiation, which may play an important role in its distant metastasis. The underlying molecular biological and pathological mechanisms of benign SFT malignance transformation still warrant further exploration.

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.

Pediatric sellar solitary fibrous tumor/ hemangiopericytoma: A rare case report and review of the literature

Background:

Solitary fibrous tumor (SFT)/hemangiopericytoma (HPC) is a rare tumor which originates from the walls of capillaries and has historically been thought to be able to occur anywhere in the body that blood vessels are found. It is rarely found in the sellar region.

Case Description:

InS this report, we present the first case of this tumor occurring in the sellar region of a pediatric patient. This 12-year-old male presented with progressive vision loss which prompted surgical resection after a sellar lesion was discovered on imaging. The initial transsphenoidal approach resulted in subtotal resection and the patient experienced reoccurrence within 3 months. He underwent an orbitozygomatic craniotomy to achieve gross total tumor resection.

Conclusion:

We conducted a literature review of intracranial SFT/HPC in the pediatric population and found it to be an extremely rare occurrence, with <30 cases reported. The incidence of SFT/HPC occurring in the sellar region for any age group was also found to be a rare entity. Treatment recommendations for this tumor are also scarce, based on retrospective chart reviews from the adult population. The role for adjuvant radiation has mixed results.

Intracranial anaplastic solitary fibrous tumor/hemangiopericytoma: immunohistochemical markers for definitive diagnosis

Intracranial anaplastic hemangiopericytoma (AHPC) is a rare and malignant subset of solitary fibrous tumor/hemangiopericytoma (SFT/HPC) as per the WHO 2016 Classification of Tumors of the Central Nervous System. AHPC portends a poor prognosis and is associated with higher rates of recurrence/metastasis in comparison with SFT/HPC. Accordingly, it is critical to continue to define the clinical course of patients with AHPC and in so doing further refine clinicopathologic/immunohistochemical (IHC) criteria needed for definitive diagnosis. Herein, we describe clinical/histological characteristics of six patients with AHPC. In addition, we reviewed and analyzed the expression of various IHC markers reported within the literature (i.e., a total of 354 intracranial SFT/HPCs and 460 meningiomas). Histologically, tumors from our six patients were characterized by a staghorn-like vascular pattern, mitotic cells, and strong nuclear atypia. Immunohistochemically, all tumors displayed positive nuclear staining for STAT6; other markers, including CD34 and Bcl-2, were expressed only in three patients. Analysis of IHC expression patterns for SFT/HPC and meningioma within the literature revealed that nuclear expression of STAT6 had the highest specificity (100%) for SFT/HPC, followed by ALDH1 (97.2%) and CD34 (93.6%). Of note, SSTR2A (95.2%) and EMA (85%) displayed a high specificity for meningioma. Anaplastic SFT/HPC is a tumor with poor prognosis that is associated with higher rates of recurrence and metastasis in comparison with SFT/HPC. Given that anaplastic SFT/HPC requires more aggressive treatment than meningioma despite of a similar presentation on imaging, it is crucial to be able to distinguish between these tumors.

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.

Hemangiopericytomas: Spatial Intracranial Location in a Voxel-Based Mapping Study

BACKGROUND AND PURPOSE

To investigate the preferred location of intracranial hemangiopericytomas (IHPCs) with voxel-based mapping and 3-dimensional reconstruction from MRI data.

METHODS

Gadolinium-enhanced tumors of 258 primary and single IHPCs were segmented semi-automatically, followed by manual checking and editing of boundaries. The lesions were registered to Montreal Neurological Institute standard anatomical space, and heat-map and 3-dimensional rendered frequency images were generated. All tumors were then superimposed on the Anatomical Automatic Labeling (AAL) template to further investigate the difference in the tumor location based on the voxel-wise frequency of occurrence with respect to laterality, sex, age, and pathologic grade.

RESULTS

The 3-dimensional rendered images show that the tumors commonly located in the posterior cranial cavity, surrounding the tentorium. The posterior third of the superior sagittal sinus and the confluence of sinuses were commonly affected. According to the analysis of tumor occurrence frequency in the AAL template, IHPCs were mainly observed in the limbic lobe, occipital lobe, and cerebellum. Tumors in younger patients preferentially located in the right occipital region (P = .027), whereas those with higher pathological grade more often located in the left parietal lobe (P = .034).

CONCLUSIONS

This is the first voxel-based study to explore the predilection site of IHPCs. Our study suggests that these tumors commonly affect the posterior cranial cavity, adjoining the tentorium and venous sinus. Further research is needed to investigate the possible factors underlying these topographic preferences.

Nervous System Hemangiopericytoma

The management of patients harboring central nervous system (CNS) hemangiopericytomas (HPCs) is a partially answered challenge. These are rare locally aggressive lesions, with potential for local recurrence, distal neural metastasis (DNM), and extraneural metastasis (ENM). Resection, when feasible, remains the initial treatment option, providing histological diagnosis and immediate relief of tumor-related mass effect. Patients receiving surgery alone or surgery and external beam radiotherapy (EBRT) show improved overall survival (OS) and progression-free survival as compared to those undergoing a biopsy alone (p = 0.01 and p = 0.02, respectively). Yet, in many instances, patient and tumor-related parameters preclude complete resection. EBRT or stereotactic radiosurgery (SRS) shares a significant role in achieving local tumor control, not shown to impact OS in HPC patients. The benefits of SRS/EBRT are clearly limited to improved local tumor volume control and neurologic function, not affecting DNM or ENM development. SRS provides acceptable rates of local tumor volume control coupled with treatment safety and a patient-friendly apparatus and procedure. Single-session SRS is most effective for lesions measuring <2 cm in their largest diameter (10 cm3 volume), with prescription doses of at >15 Gy. Systemic HPC disease is managed with various chemotherapeutic, immunotherapeutic, and anti-angiographic agents, with limited success. We present a short discussion on CNS HPCs, focusing our discussion on available evidence regarding the role of microsurgical resection, EBRT, SRS, chemotherapy, and immunotherapy for upfront, part of adoptive hybrid surgery approach or for recurrent HPCs.

Non-islet cell tumor-induced hypoglycemia in the setting of metastatic intracranial hemangiopericytoma: case report and review of the literature

Intracranial hemangiopericytoma, particularly in the setting of extracranial metastatic disease, can cause severe hypoglycemia; but there is limited description of this phenomenon in the neurosurgical literature. We report the case of a male patient with recurrent meningeal hemangiopericytoma that had metastasized to multiple extracranial locations, who presented with severe, symptomatic hypoglycemia and abnormal levels of insulin, pro-insulin, insulin-like growth factors I and II, and C-peptide. This case highlights the association between hemangiopericytoma and abnormal levels of peptide hormones involved in glucose homeostasis, which may serve as a warning sign for hemangiopericytoma and/or metastatic disease.

Intracranial anaplastic hemangiopericytoma presenting with simultaneous extra-cranial metastases: A case report and review of the literature

Background:

Intracranial solitary fibrous tumor/hemangiopericytoma (SFT/HPC) is a rare mesenchymal tumor with a propensity to recur and metastasize extracranially years after treatment. Accordingly, there are no reported cases of a patient presenting with a simultaneous intracranial primary and extracranial metastases. We present the case of a patient presenting with an intracranial SFT/HPC and simultaneous liver metastases and propose a treatment paradigm.

Case Description:

A 74-year-old male smoker presented with confusion. An MRI of the brain revealed a heterogeneously enhancing left frontal extra-axial mass. Systemic workup revealed multiple small liver lesions concerning for metastases. The patient underwent gross total resection (GTR) of the intracranial lesion with adjuvant CyberKnife stereotactic radiotherapy to the resection cavity. Pathology was consistent with a WHO Grade III SFT/HPC (previously known as anaplastic HPC). The liver lesions were biopsied and confirmed to be metastases. They were subsequently treated with stereotactic body radiation therapy, temozolomide, and bevacizumab. Eighteen months postoperatively, the patient is alive with no evidence of intracranial malignancy and regression of the hepatic lesions.

Conclusion:

Several studies support GTR and adjuvant radiotherapy to treat intracranial SFT/HPC. The role of adjuvant chemotherapy is less clear. Metastatic disease is typically detected several years after the initial diagnosis, and there is no consensus regarding the optimal treatment strategy. We propose that the rare presentation of intracranial SFT/HPC with simultaneous extracranial metastases should be treated in a multidisciplinary fashion with surgical resection, adjuvant radiotherapy, and chemotherapy.

Coexistence of intracranial solitary fibrous tumor/hemangiopericytoma and right middle cerebral artery aneurysm

Intracranial solitary fibrous tumors are rare mesenchymal neoplasms originating in the meninges and constitute a heterogeneous group of rare spindle cell tumors that include benign and malignant neoplasms of which hemangiopericytoma is nowadays considered a cellular phenotypic variant. From literatures, the incidence of coexistence of brain tumors and intracranial aneurysms is ~0.7-5.4%. Meningioma is the most frequent tumor coexisted with intracranial aneurysms, followed by pituitary adenoma, neuroepithelial tumor, and metastatic tumor. We would like to report a case of 74-year-old man harboring a rare intracranial solitary fibrous tumor/hemangiopericytoma and an unruptured aneurysm of the right middle cerebral artery which probably the first report of these combinations in the English literature. Both lesions were treated surgically in one session with favorable outcome. Magnetic resonance angiography should be performed in patients with brain tumor preoperatively not only to visualize neoplastic vascularization but also to pick up incidental aneurysm.