Descriptive epidemiology of 399 histologically confirmed newly diagnosed meningeal solitary fibrous tumours and haemangiopericytomas in France: 2006-2015.

PURPOSE: Meningeal solitary fibrous tumour (SFT) and haemangiopericytoma (HPC) are uncommon tumours that have been merged into a single entity in the last 2021 WHO Classification of Tumors of the Central Nervous System. To describe the epidemiology of SFT/HPC operated in France and, to assess their incidence. METHODS: We processed the French Brain Tumour Database (FBTDB) to conduct a nationwide population-based study of all histopathologically confirmed SFT/HPC between 2006 and 2015. RESULTS: Our study included 399 SFT/HPC patients, operated in France between 2006 and 2015, in one of the 46 participating neurosurgical centres. The incidence reached 0.062, 95%CI[0.056-0.068] for 100,000 person-years. SFT accounted for 35.8% and, HPC for 64.2%. The ratio of SFT/HPC over meningioma operated during the same period was 0.013. SFT/HPC are about equally distributed in women and men (55.9% vs. 44.1%). For the whole population, mean age at surgery was 53.9 (SD ± 15.8) years. The incidence of SFT/HPC surgery increases with the age and, is maximal for the 50-55 years category. Benign SFT/HPC accounted for 65.16%, SFT/HPC of uncertain behaviour for 11.53% and malignant ones for 23.31%. The number of resection progresses as the histopathological behaviour became more aggressive. 6.7% of the patients with a benign SFT/HPC had a second surgery vs.16.6% in case of uncertain behaviour and, 28.4% for malignant SFT/HPC patients. CONCLUSION: Meningeal SFT and HPC are rare CNS mesenchymal tumours which both share common epidemiological characteristics, asserting their merging under a common entity. SFT/HPC incidence is less that one case for 1 billion per year and, for around 100 meningiomas-like tumours removed, one SFT/HPC may be diagnosed. SFT/HPC are equally distributed in women and men and, are mainly diagnosed around 50-55 years. The more aggressive the tumour, the higher the probability of recurrence.

Pediatric upper lip myopericytoma: a case report and comprehensive review.

BACKGROUND: Myopericytoma is a rare spindle cell tumor of mesenchymal origin, typically benign, characterized by concentric proliferation of tumor cells around blood vessels within subcutaneous tissue. It primarily occurs in middle-aged adults and is often located in distal extremities, although cases have been reported in proximal extremities and head-neck regions. However, occurrences within the oral cavity are exceedingly rare. To date, literature reviews have identified only two cases in children under 10 years old and reported only five cases of myopericytoma occurring in the lip region. We provide a comprehensive review and analysis of all documented cases to better understand this condition. CASE PRESENTATION: A 7-year-old girl presented to oral and maxillofacial surgery with the discovery of a painless mass on the inner aspect of the upper lip. The diagnosis of myopericytoma was confirmed by histological examination (HE staining), alcian blue staining, and immunohistochemistry. CONCLUSIONS: Following surgical excision, there were no signs of recurrence at a 3-month follow-up. The pathological diagnosis of myopericytoma is quite challenging, and immunohistochemical testing is necessary.

Uterine hemangiopericytoma with cardiac involvement and pulmonary metastasis: A case report and literature review.

Uterine hemangiopericytoma is extremely rare. This article describes a case of uterine hemangiopericytoma. The tumor involved the parauterine vein; extended into the inferior vena cava, right cardiac cavity, and pulmonary artery; and metastasized to the lungs. It was irregular in shape and exhibited the string-of-beads sign on echocardiography, and it was tightly attached to the right ventricular surface and pulmonary artery wall. The patient underwent tumor resection without adjuvant treatment. A pelvic nodule was found 3 months postoperatively and was considered a recurrent lesion.

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.

Postoperative progression of intracranial grade II-III solitary fibrous tumor/hemangiopericytoma: predictive value of preoperative magnetic resonance imaging semantic features.

BACKGROUND: Preoperative prediction of postoperative tumor progression of intracranial grade II-III hemangiopericytoma is the basis for clinical treatment decisions. PURPOSE: To use preoperative magnetic resonance imaging (MRI) semantic features for predicting postoperative tumor progression in patients with intracranial grade II-III solitary fibrous tumor/hemangiopericytoma (SFT/HPC). MATERIAL AND METHODS: We retrospectively analyzed the preoperative MRI data of 42 patients with intracranial grade II-III SFT/HPC, as confirmed by surgical resection and pathology in our hospital from October 2010 to October 2017, who were followed up for evaluation of recurrence, metastasis, or death. We applied strict inclusion and exclusion criteria and finally included 37 patients. The follow-up time was in the range of 8-120 months (mean = 57.1 months). RESULTS: Single-factor survival analysis revealed that tumor grade (log-rank, P = 0.024), broad-based tumor attachment to the dura mater (log-rank, P = 0.009), a blurred tumor-brain interface (log-rank, P = 0.008), skull invasion (log-rank, P = 0.002), and the absence of postoperative radiotherapy (log-rank, P = 0.006) predicted postoperative intracranial SFT/HPC progression. Multivariate survival analysis revealed that tumor grade (P = 0.009; hazard ratio [HR] = 11.42; 95% confidence interval [CI] = 1.832-71.150), skull invasion (P = 0.014; HR = 5.72; 95% CI = 1.421-22.984), and the absence of postoperative radiotherapy (P = 0.001; HR = 0.05; 95% CI = 0.008-0.315) were independent predictors of postoperative intracranial SFT/HPC progression. CONCLUSION: Broad-based tumor attachment to the dura mater, skull invasion, and blurring of the tumor-brain interface can predict postoperative intracranial SFT/HPC progression.

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 hemangiopericytoma after radiation treatment: first case in the literature.

BACKGROUND: Radiation exposure is a known risk factor for meningioma but there are no data regarding hemangiopericytoma and radiation exposure. CASE DESCRIPTION: We report a 29-year-old pineoblastoma patient diagnosed with a hemangiopericytoma at a different location, after a successful surgical excision and adjuvant radiotherapy for the original tumor 4-year prior. CONCLUSION: Hemangiopericytoma emergence can be seen after radiotherapy.

Treatment and Management of a Sinonasal Hemangiopericytoma.

Sinonasal Hemangiopericytoma (HPC) is a rare vascular tumor originated from Zimmermann's pericyte with not well valuable course. The diagnosis needs a careful ENT endoscopic examination, radiological study and histopathological analysis with immunohistochemistry for confirmation of diagnosis. We describe a case of a male patient, 67 years old, with history of repeated monolateral right epistaxis. Endoscopic and radiological examination showed an ethmoid-sphenoidal lesion which occupied the entire nasal fossa extending towards the choana, with blood supply coming from the posterior ethmoidal artery. The patient performed an extemporaneous biopsy with subsequent en-bloc removal in operating room, without prior embolization, with the Centripetal Endoscopic Sinus Surgery technique (CESS). The histopathologic analysis led to the diagnosis of sinus HPC. The patient performed close endoscopic follow-ups every 2 months, without performing radio or chemotherapy, and with no evidence of recurrence after 3 years of follow-up. Analyzing the recent literature, a more indolent course with low recurrence rates after total endoscopic surgery remotion was described. Preoperative embolization can be useful in determinate cases, but cause to different complications, it should not be ordinarily performed.

Intracranial Solitary Fibrous Tumor Mimicking Meningioma.

Solitary fibrous tumor (SFT) is a clinically rare tumor derived from mesenchymal spindle cells. Central nervous system SFT represents only 0.09% of tumors occurring on the meninges, while intracranial solitary fibrous tumors (ISFT) are even more rare. Due to the similar genetic characteristics it shares with hemangiopericytoma, in 2016, the World Health Organization (WHO) classified it as a single disease called solitary fibrous tumor (SFT)/hemangiopericytoma. We reported a case of a 60-year-old female with an intracranial solitary fibrous tumor (ISFT). The patient's magnetic resonance imaging showed a mass adhering extensively to the dura mater, with adjacent thickening of the meninges and evidence of a meningeal tail sign. These radiologic findings suggested a meningioma. The tumor was surgically removed and sent for pathologic examination, which confirmed that the tumor was consistent with a solitary fibrous tumor(WHO III). Due to its rarity and similarities with meningioma, ISFT is often misdiagnosed as other types of brain tumors. ISFT is poorly understood and poses a diagnostic challenge. Our case report presents several features suggestive of meningioma, but histopathological examination after surgery confirmed the diagnosis of SFT. Knowledge of these tumors is crucial for neurosurgeons to include them in preoperative differential diagnosis.

The relationship between the apparent diffusion coefficient and the Ki-67 proliferation index in intracranial solitary fibrous tumor/hemangiopericytoma.

This study evaluated the value of the apparent diffusion coefficient (ADC) in distinguishing grade II and III intracranial solitary fibrous tumors/hemangiopericytomas and explored the correlation between ADC and Ki-67. The preoperative MRIs of 37 patients treated for solitary fibrous tumor/hemangiopericytoma (grade II, n = 15 and grade III, n = 22) in our hospital from 2011 to October 2020 were retrospectively analyzed. We compared the difference between the minimum, average, maximum, and relative ADCs based on tumor grade and examined the correlation between ADC and Ki-67. Receiver operating characteristic curve analysis was used to analyze the diagnostic efficiency of the ADC. There were significant differences in the average, minimum, and relative ADCs between grade II and III patients. The optimal cutoff value for the relative ADC value to differentiate grade II and III tumors was 0.998, which yielded an area under the curve of 0.879. The Ki-67 proliferation indexes of grade II and III tumors were significantly different, and the average (r = - 0.427), minimum (r = - 0.356), and relative (r = - 0.529) ADCs were significantly negatively correlated with the Ki-67 proliferation index. ADC can be used to differentiate grade II and III intracranial solitary fibrous tumors/hemangiopericytomas. Our results can be used to formulate a personalized surgical treatment plan before surgery.

Differentiation of intracranial solitary fibrous tumor/hemangiopericytoma from atypical meningioma using apparent diffusion coefficient histogram analysis.

This study aimed to investigate the value of apparent diffusion coefficient (ADC) histogram analysis in differentiating intracranial solitary fibrous tumor/hemangiopericytoma (SFT/HPC) from atypical meningioma (ATM). Retrospective analyzed the clinical, magnetic resonance imaging, and pathological data of 20 and 25 patients with SFT/HPC and ATM, respectively. Histogram analysis was performed on the axial ADC images using MaZda software, and nine histogram parameters were obtained, including mean, variance, skewness, kurtosis, and the 1st (ADC1), 10th (ADC10), 50th (ADC50), 90th (ADC90), and 99th (ADC99) percentile ADC. Differences in ADC histogram parameters between SFT/HPC and ATM were compared by an independent t test or Mann-Whitney U test, while the statistically significant histogram parameters were further analyzed by drawing receiver operating characteristic (ROC) curves to evaluate the differential diagnostic performance. Among the nine ADC histogram parameters we extracted, the mean, ADC1, ADC10, ADC50, and ADC90 in the SFT/HPC group were greater than those of ATM, and significant differences were observed (all P < 0.05). ROC analysis showed that the ADC1 generated the highest area under the curve (AUC) value of 0.920 in distinguishing the two tumors, when using 91.00 as the optimal threshold. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value in distinguishing between SFT/HPC and ATM were 84.00%, 85.00%, 84.44%, 87.50%, and 81.00%, respectively. ADC histogram analysis can be a reliable tool to differentiate between SFT/HPC and ATM, with the ADC1 being the most promising potential parameter.

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.

Sino-nasal hemangiopericytoma: a case series and systematic literature review.

BACKGROUND: Hemangiopericytoma is a rare tumor of the sino-nasal tract. Its clinical behavior is controversial. Whereas some describe an indolent course, others consider it to be an aggressive lesion with a tendency toward rapid local recurrence. Here, we describe our experience in the management of sino-nasal hemangiopericytoma (SN-HPC), comparing our experience with the current literature, and evaluating signs and tools to improve diagnosis and treatment. METHODS: All cases of SN-HPC between 2010 and 2020 were extracted and reviewed from our institutional electronic medical records. SN-HPC cases from PubMed and EMBASE between 2010 and 2020 were analyzed in a systematic literature review using the preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines. Data regarding demographics, presentation, diagnosis, treatment, and outcome were collected. RESULTS: We identified four cases of SN-HPC in the nasal cavity in our institution and an additional 53 cases in previous reports. The mean age at the time of diagnosis was 59 years, with a 1.2:1 male to female ratio. SN-HPC mostly appears unilaterally, arising in the ethmoid sinus (42.1%). The most common presenting symptoms were epistaxis (47.3) and nasal obstruction (47.3%). Both computed tomography (CT) and magnetic resonance imaging (MRI) were required for diagnosis and for tailoring the treatment plan. Endoscopic surgical excision was used in 85.9% of the patients, and in 15.7%, an additional preoperative embolization was performed, which was associated with septal necrosis in one patient (2.6%). The recurrence rate was 7%. CONCLUSION: Although previous reports attribute an aggressive tumoral behavior to SN-HPC, our experience and the literature review support a more indolent course with low recurrence rates following complete endoscopic resection. Preoperative embolization can be useful in certain cases, but due to potential complications, it should not be routinely indicated.

Hemangiopericytoma/solitary fibrous tumor of the cranial base: a case series and literature review.

BACKGROUND: Hemangiopericytomas (HPCs) are uncommon soft tissue tumors. HPCs that grow in the cranial base are rare. Therefore, skull-base surgeons tend to overlook this disease. This study aimed to increase the awareness of HPCs by summarizing case data from our institution and related publications. We also aimed to contribute to the number of reported cases for future systematic reviews of HPCs. METHODS: This study included all patients who underwent surgery for HPC/solitary fibrous tumor (SFT) between August 2015 and August 2019. All surgeries were performed at Xiangya Hospital Central South University. We analyzed clinical characteristics, surgical highlights, treatment modalities, and outcomes. RESULTS: We included six patients, aged 32-64 years. Lesions were located in the parapharyngeal space in three patients, pterygopalatine fossa in two, and saddle area in one. All patients underwent nasal endoscopic endonasal surgery. In five patients, tumors involved the internal carotid artery (ICA). The exposure and protection of the ICA during surgery are challenging but critical to complete tumor removal. The 3-year overall survival(OS) rate was 66.7%. CONCLUSIONS: HPC/SFTs are rare tumors of the cranial base that are prone to recurrence. Cranial base HPC/SFTs are often closely associated with the ICA. To our knowledge, this case series reports the largest number of cases of HPCs associated with the ICA. We believe that there is a strong relationship between patient prognosis and whether the tumor encircles the ICA and whether the tumor is completely resected. To confirm this suggestion, more cases are needed for further analysis.

[Solitary fibrous tumor/hemangiopericytoma].

Solitary fibrous tumor(SFT)/hemangiopericytoma(HPC)is a rare mesenchymal tumor with propensity for recurrence and metastasis. Although SFT and HPC were initially considered to be distinct entities, the identification of NAB2-STAT6 fusion as a definitive molecular alteration in both tumors has led to their integration into one disease entity, for both meningeal and non-meningeal lesions. This fusion leads to a nuclear relocation of the STAT6 protein and is detectable with immunohistochemistry. STAT6 immunohistochemistry has been shown to have excellent sensitivity and specificity for histological diagnosis. Although these discoveries have improved the diagnosis of SFT/HPC, the association of the NAB2-STAT6 fusion status with phenotype and prognosis remains unclear, and accurate prognostic factors have not been established. This comprehensive review provides current knowledge on the clinical, histological, and molecular characteristics of SFT/HPC.

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.

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 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.

Primary endodermal hemangiopericytoma/solitary fibrous tumor of the cervical spine: a case report and literature review.

BACKGROUND: Hemangiopericytoma (HPC), also known as solitary fibrous tumor (SFT), is a type of soft tissue sarcoma with a special aggressive behavior. The HPC/SFT is locally aggressive with possibility of late recurrence locally or distant extraneural metastasis. The most common location of this HPC/SFT is the lower extremities. The HPC/SFT in the central nervous system (CNS) is very rare, and compared with the brain, it is rarer in the spinal region. However, clinicians also lack an overall understanding of the diagnosis of HPC/SFT in the spinal cord. CASE PRESENTATION: In this study, we report a rare case of primary cervical spine HPC/SFT in a 53-year-old woman. Two to three weeks before admission, she experienced pain and numbness in her left upper extremity. After computerized tomography (CT) and magnetic resonance imaging (MRI), a gross total resection was performed. Obvious neurological improvement was observed postoperatively. The pain and numbness in the patient's left upper limb were relieved subsequently. We then reviewed the literature on HPC/SFT, such as its clinical presentation, imaging characteristics, treatment, and follow-up. CONCLUSIONS: Diagnosis of HPC/SFT relies on magnetic resonance spectroscopy, enhanced CT, and MRI. Postoperative radiotherapy is strongly recommended to reduce the HPC/SFT recurrence. Immunohistochemical analysis can also help in the differential diagnosis. However; early and long-term follow-up is necessary for patients.

Presentation of Infantile Hemangiopericytoma/Solitary Fibrous Tumor as a Giant Extracranial Temporal Mass.

BACKGROUND: Infantile Hemangiopericytoma (HPC)/Solitary Fibrous Tumor (SFT), a vascular tumor of head and neck region, can be congenital or arise during the first year of the life. As the infantile form of hemangiopericytoma has a better course than the adult form, surgical excision is recommended. Case Report: A full-term neonate presented with a congenital right temporal soft tissue mass. MRI revealed a highly vascular mass with a hemorrhagic and possible necrotic core without intracranial extension. The lesion grew in 2 weeks from 4x4 cm to 9x7 cm. Histologically, a hypercellular spindle cell mesenchymal neoplasm had prominent staghorn vessels, alternating with hypocellular areas. Mitotic activity was low(1-3/HPF) and necrosis was absent. Conclusion: Infantile HPC/SFT of head and neck can grow rapidly during the infantile period. Complete excision without mutilating surgery should be curative.