Hemangiopericytoma Research Articles

Spinal location is prognostic of survival for solitary-fibrous tumor/hemangiopericytoma of the central nervous system.

Prior studies have highlighted infratentorial tumor location as a prognostic factor for solitary fibrous tumor (SFT) and hemangiopericytoma (HPC) of the central nervous system (CNS), and spinal location is considered a positive prognostic factor for other tumors of the CNS. While SFT/HPC of the CNS is known to frequently arise from the spinal meninges, there are no case series that report outcomes for spinally located CNS tumors, and their prognosis in relation to intracranial and other CNS-located tumors is unknown. To investigate outcomes for patients with SFT/HPC of the spinal meninges. The Surveillance, Epidemiology, and End-Results Program was used to identify patients with SFT/HPC within the CNS from 1993-2015. We retrospectively analyzed the relationship between tumor location (spinal vs. Brain and other CNS) and survival. We identified 551 cases of CNS SFT/HPC, 64 (11.6%) of which were primary tumors of the spinal meninges. Spinal tumors were more likely than brain and other CNS tumors to be SFT vs. HPC (37.5 vs. 12%, p < 0.001), benign (42.2 vs. 20.3%, p < 0.001), and less than 5cm (53.1 vs. 35.7%, p < 0.001). The 10-year survival rates for spinal and brain/other CNS tumors were 85 and 58%, respectively. Median survival time was significantly longer for spinal tumors (median survival not reached vs. 138months, p = 0.03, HR = 0.41 [95% CI 0.18-0.94]). On multivariable analysis, spinal tumor location was associated with improved survival over tumors located in the brain and other CNS (HR = 0.36 [95% CI 0.15-0.89], p = 0.03). Spinal tumor location is associated with improved survival in patients with SFT/HPC of the CNS. Larger institutional studies are necessary to characterize the relationship between tumor location and other relevant factors such as presentation and amenability to gross-total resection and adjuvant radiotherapy. Future studies exploring optimal management of spinally located tumors are also needed.

Frozen Cytology of Meningeal Malignant Solitary Fibrous Tumor/Hemangiopericytoma.

A 51-year-old woman presented with severe dizziness. The brain magnetic resonance image revealed a 5.5 cm multiloculated mass with a thick rim in the left temporal lobe. Cytological examination of frozen diagnosis of the mass showed hypercellular sheets of round and rhabdoid cells in a hemorrhagic background, and two mitotic figures were observed. Histologically, the excised dura-based mass consisted of predominantly round cells with small foci of rhabdoid tumor cells in a pseudoalveolar pattern in a hemorrhagic background, and the cells showed nuclear positivity for signal transducer and activator of transcription 6 as well as frequent mitosis. The mass was diagnosed as a grade 3 solitary fibrous tumor (SFT)/hemangiopericytoma (HPC). The cytological diagnosis of SFT/HPC is challenging because of the heterogeneous cytological findings, such as histological heterogeneity, and because there are no standardized cytological criteria for malignant SFT/HPC. Cytological findings, such as singly scattered small cells, hypercellularity, rare ropy collagen, and round and rhabdoid cells with pseudoalveolar pattern, may assist in the diagnosis of malignant SFT/HPC.

50. Grade 3 haemangiopericytoma of parafalcine region of brain

Background: Haemangiopericytoma (HPC) is a rare tumour (accounting for <1% of all primary CNS tumours). HPC behaves aggressively with a high rate of local recurrence and distant metastases and most commonly affects adults of 4th to 6th decade of life. HPC closely mimics meningioma in clinical and radiological features, thus, its diagnosis and treatment is a challenge.

STAT6 immunohistochemical expression in meningeal-based tumors: Diagnostic of solitary fibrous tumor/hemangiopericytomas

Background: Updated 2016 WHO classification of central nervous system tumors has unified solitary fibrous tumor (SFT) and hemangiopericytoma (HPC) as a single entity (SFT/HPC), Grading from I to III, in view of common genetic alteration namely fusion of NAB2 and STAT6 genes. Aim: This study aims to evaluate the role of STAT6 immunohistochemical expression in a cohort of meningeal-based tumors and its correlation with other pathological parameters. Materials and Methods: Sixty-two meningeal-based tumors were studied including 40 HPC/SFT (1 Grade I, 29 Grade II and 10 Grade III), 14 meningiomas (2 Grade I, 10 Grade II, 2 anaplastic meningiomas), three meningeal sarcoma, and five cases with features suspicious for SFT/HPC. The expression pattern of STAT6 and other histological findings were noted. Results: Nuclear or nuclear + cytoplasmic STAT6 positivity was seen in 40/40SFT/HPC (100%), diffuse in 30 and focal in 10 cases. Only 1/14 cases of meningioma (7.1%) showed weak nuclear positivity. All cases of meningiomas and 2/3 cases of meningeal sarcoma showed cytoplasmic positivity. Of the five suspicious HPC cases, four showed diffuse strong nuclear STAT6 positivity, based on which they were confirmed as HPC. Interestingly, of the 40 STAT6 positive SFT/HPC, five showed epithelial differentiation (AE1/AE3 and/or epithelial membrane antigen [EMA]). CD34 was negative in 4/36 SFT/HPC. CD34 was focally positive in 3/5 suspicious HPC cases, two of which were focally EMA positive as well, and both cases showed nuclear STAT6 positivity. BCl2 was negative in 5/27 SFT/HPC, all of which were nuclear STAT6 positive. Conclusions: Nuclear expression of STAT6 can serve as a highly sensitive and specific adjunctive diagnostic marker for meningeal-based SFT/HPC, especially in cases with nonconventional histology and immunohistochemical profile, where meningioma or high-grade meningeal sarcoma forms a diagnostic dilemma.

Glomangiopericytoma: A rare sinonasal tumor in a young female

Glomangiopericytoma (GPC)/sinonasal type hemangiopericytoma (HPC) is a rare sinonasal neoplasm arising from the pericytes surrounding capillaries and accounts for <0.5% of all sinonasal tumors. This tumor differs from conventional soft-tissue HPC in location, biologic behavior, and histologic features. GPC is a borderline tumor of low malignant potential with a good prognosis after complete surgical resection. We report a case of a 20-year-old woman who presented with progressive nasal obstruction and frequent nasal bleeding and was diagnosed as GPC on histopathological and immunohistochemistry findings. Histological characteristics, differential diagnosis, and prognosis of this tumor are discussed in this article. This case has been reported because of its rarity and an array of differential diagnosis.

Management of Patients with Hemangiopericytoma: Case Report and Literature Review

The hemangiopericytomas (HPCs) are rare tumors of the dural base and correspond of less than 1% of all primary Central Nervous System (CNS) tumors. It usually affects adult males with 40 to 50 years old and has a supratentorial location (70%), followed by posterior fossa (15%) and spine (15%). Generally, it has fast progression and manifests clinically through headache, focal neurological deficits and epileptic seizures. The tumor has high incidence of local recurrence, from 34% to 90%, and it is estimated that the follow-up of these patients should be done for at least 7, 5 years. The percentage of long-distance metastases is lower, 12% to 55%, affecting especially bones, lungs and liver, in decreasing order. The objective of this study is to evaluate the contradictions when approaching these tumors and to analyze a rare case of pediatric involvement. It was prepared a case report and a literature review was made using the data bases MEDLINE®, PubMed and Cochrane, where 31 relevant articles were selected related to the proposed study. The outcome of HPC treatment can change according to the tumor’s location in the CNS or extracranial, the tumor’s size and the histopathological classification. Therefore, many studies have been proposed observing the answer of the surgical resection, the adjuvant radiotherapy, the radiosurgery and the antiangiogenic therapies.

The impact of histopathology and NAB2\u2013STAT6 fusion subtype in classification and grading of meningeal solitary fibrous tumor/hemangiopericytoma

Meningeal solitary fibrous tumor (SFT)/hemangiopericytoma (HPC) is a rare tumor with propensity for recurrence and metastasis. Although multiple classification schemes have been proposed, optimal risk stratification remains unclear, and the prognostic impact of fusion status is uncertain. We compared the 2016 WHO CNS tumor grading scheme (CNS-G), a three-tier system based on histopathologic phenotype and mitotic count, to the 2013 WHO soft-tissue counterpart (ST-G), a two-tier system based on mitotic count alone, in a cohort of 133 patients [59 female, 74 male; mean age 54 years (range 20–87)] with meningeal SFT/HPC. Tumors were pathologically confirmed through review of the first tumor resection (n = 97), local recurrence (n = 35), or distant metastasis (n = 1). A STAT6 immunostain showed nuclear expression in 132 cases. NAB2–STAT6 fusion was detected in 99 of 111 successfully tested tumors (89%) including the single STAT6 immunonegative tumor. Tumors were classified by CNS-G as grade 1 (n = 43), 2 (n = 41), or 3 (n = 49), and by ST-G as SFT (n = 84) or malignant SFT (n = 49). Necrosis was present in 16 cases (12%). On follow-up, 42 patients had at least one subsequent recurrence or metastasis (7 metastasis only, 33 recurrence only, 2 patients had both). Twenty-nine patients died. On univariate analysis, necrosis (p = 0.002), CNS-G (p = 0.01), and ST-G (p = 0.004) were associated with recurrence-free (RFS) but not overall survival (OS). NAB2–STAT6 fusion type was not significantly associated with RFS or OS, but was associated with phenotype. A modified ST-G incorporating necrosis showed higher correlation with RFS (p = 0.0006) and remained significant (p = 0.02) when considering only the primary tumors. From our data, mitotic rate and necrosis appear to stratify this family of tumors most accurately and could be incorporated in a future grading scheme.

Solitary Fibrous Tumor/Hemangiopericytoma of Spinal Cord: A Retrospective Single-Center Study of 16 Cases

In this study, we retrospectively reviewed our experience in the surgical management of solitary fibrous tumor (SFT)/hemangiopericytomas (HPCs) of the spinal cord. Sixteen patients with SFT/HPCs of the spinal cord were enrolled in this study. Data on clinical presentation, radiologic findings, histopathologic features, surgical treatment, adjuvant therapy, and prognosis were retrospectively reviewed. Kaplan-Meier curves and log-rank tests were used to identify the prognostic factors for recurrence and overall survival (OS). Our series included 6 men and 10 women, with a male/female ratio of 1:1.7. Magnetic resonance imaging (MRI) showed slightly hyperintense lesions on T2-weighted images for all 16 patients. All tumors showed positive immunohistochemical staining for signal transducer and activator of transcription 6. Statistical analysis of clinical data showed that age, gender, tumor location, tumor size, medullary compartment location, and Ki-67 index were not associated with recurrence and OS (P > 0.05). However, World Health Organization grade III was significantly associated with recurrence (P < 0.01). Gross total resection (GTR) and postoperative radiotherapy significantly reduced recurrence (P < 0.01 and P < 0.05), but only GTR showed remarkable benefits to improve OS (P < 0.05). SFT/HPCs of spinal cord are rare neoplasms with a propensity to recur. Hyperintensity on T2-weighted magnetic resonance imaging combined with positive immunohistochemical staining for signal transducer and activator of transcription 6 are important clues for classification and differentiation of these tumors. The extent of resection, World Health Organization grade, and postoperative radiotherapy might be predictive factors for recurrence. Complete tumor resection should be sought whenever possible, and adjuvant radiotherapy is recommended after surgical resection. Moreover, regular and long-term follow-up is mandatory to monitor recurrence.

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

OBJECTIVEThe authors conducted this retrospective study to investigate the clinical outcomes of intracranial solitary fibrous tumor (SFT) and hemangiopericytoma (HPC), defined according to the 2016 WHO classification of central nervous system (CNS) tumors.METHODSHistopathologically proven intracranial SFT and HPC cases treated in the period from June 1996 to September 2014 were retrospectively reviewed and analyzed. Two neuropathologists reviewed pathological slides and regraded the specimens according to the 2016 WHO classification. Factors associated with progression-free survival (PFS) and overall survival (OS) were statistically evaluated with uni- and multivariate analyses.RESULTSThe records of 47 patients-10 with SFT, 33 with HPC, and 4 with anaplastic HPC-were reviewed. A malignant transition from conventional SFT to WHO grade III SFT/HPC was observed in 2 cases, and 13 HPC cases were assigned grade III SFT/HPC. Mean and median follow-ups were 114.6 and 94.7 months, respectively (range 7.1-366.7 months). Gross-total resection (GTR) was significantly associated with longer PFS and OS (p = 0.012 for both), and adjuvant radiation therapy versus no such therapy led to significantly longer PFS (p = 0.018). Extracranial metastases to the liver, bone, lung, spine, and kidney occurred in 10 patients (21.3%). Grade III SFT/HPC was strongly correlated with the development of extracranial metastases (p = 0.031).CONCLUSIONSThe 2016 WHO classification of CNS tumors reflected the different types of pathological malignant progression and clinical outcomes better than prior classifications. Gross-total resection should be the primary treatment goal in patients with SFT/HPC, regardless of the pathological grade, and radiation can be administered as adjuvant therapy for patients with SFT/HPC that shows an aggressive phenotype or that is not treated with GTR.

Preoperative Prediction of Solitary Fibrous Tumor/Hemangiopericytoma and Angiomatous Meningioma Using Magnetic Resonance Imaging Texture Analysis

Solitary fibrous tumor (SFT)/hemangiopericytoma (HPC) is radiologically difficult to distinguish from meningioma, especially angiomatous meningioma. This study aimed to detect texture parameters to distinguish SFT/HPC from angiomatous meningioma using magnetic resonance imaging texture analysis with commercially available software. We retrospectively investigated textural parameters in 43 newly diagnosed SFTs/HPCs, angiomatous meningiomas, and other World Health Organization (WHO) grade I meningiomas treated at Keio University Hospital. For T1 contrast-enhanced, T2, and apparent diffusion coefficient (ADC) images, texture analyses were performed. Regions of interest were drawn manually with reference to the greater signal on contrast-enhanced T1-weighted images. ADC values and texture parameters, including kurtosis, skewness, and entropy, were evaluated and compared between these 3 groups. The mean ADC value was significantly high in angiomatous meningioma, compared with SFT/HPC and other WHO grade I meningioma. ADC entropy was highest in SFT/HPC, followed by angiomatous and other WHO grade I meningioma. T2 skewness was significantly high in SFT/HPC, compared with angiomatous and other WHO grade I meningioma. T1 contrast-enhanced skewness was significantly low in angiomatous meningioma, compared with other WHO grade I meningioma. Mean ADC value distinguished SFT/HPC from angiomatous meningioma with a positive predictive value (PPV) of 62.5% and specificity of 62.5%. ADC entropy distinguished SFT/HPC from angiomatous meningioma with a PPV of 100% and specificity of 100%. ADC skewness distinguished SFT/HPC from angiomatous meningioma with a PPV of 66.7% and specificity of 71.4%. This study demonstrated that magnetic resonance imaging texture analysis was useful for distinguishing SFT/HPC from meningioma, especially angiomatous meningioma.

High p16 Expression Is Associated with Malignancy and Shorter Disease-Free Survival Time in Solitary Fibrous Tumor/Hemangiopericytoma.

Objective Solitary fibrous tumors (SFT) and hemangiopericytomas (HPC) are now classified along a single spectrum of fibroblastic mesenchymal tumors with NAB2-STAT6 fusion. This fusion acts as a driver mutation that constitutively activates EGR1, which is known to be involved in the p16 pathway. Overexpression of p16 is associated with malignancy and worse prognosis in multiple mesenchymal tumors. The authors sought to investigate p16 immunoexpression in association with malignancy and prognosis of SFT/HPC tumors. Design Twenty-three SFT/HPC tumors (central nervous system [CNS]: 12, non CNS: 11) diagnosed at our institution from 2002 to 2016 were assigned into 3 grades. Data from microarray immunohistochemistry for STAT6, synaptophysin, CD56, chromogranin, SST2A, EGR1, Ki67, and p16, grade and survival were analyzed. Results CNS SFT/HPCs tend to be malignant (grade 3; 67 vs. 18%, p = 0.036) and more likely to express synaptophysin (33 vs. 0%, p = 0.035) than non CNS tumors. Overexpression of p16 (immunopositivity ≥ 50% tumor cells) was associated with malignant (grade 3) tumors, and has a sensitivity of 70% (7/10), and a specificity of 77% (10/13), as a predictive marker for malignancy. SFT/HPC patients with low p16 expression demonstrated significantly longer disease-free survival time (median survival > 113 months) than those with high p16 expression (median survival = 30 months, p = 0.045). Conclusions SFT/HPCs in the CNS are more likely to be malignant than the tumors in other sites. High p16 expression is also associated with malignancy and shorter disease-free survival time in SFT/HPC tumors in our study cohort. Clinically, p16 overexpression can be used as predictive marker for malignancy and prognosis and a possible therapeutic target.

A novel mouse model of hemangiopericytoma due to loss of Tsc2.

Hemangiopericytoma (HPC) is a rare vascular tumor, which is thought to originate from pericytes. However, no direct evidence for the cell of origin has been found, and the mechanism of HPC tumorigenesis is poorly understood. Here we report that loss of the tumor suppressor gene Tsc2 in pericytes using a FoxD1 promoter driven cre allele (Foxd1tm1(GFP/cre) Amc, FoxD1GC) leads to the formation of HPC in multiple sites. Tsc2ffFoxD1GC mice had stunted growth with seizures and tail and hind limb tremor with a median survival of 110 days. They also showed recombination in brain, spinal cord, tongue, liver, intestine and skeletal muscle. Distinctive perivascular tumors consisting of cells with oval nuclei and scant cytoplasm were identified in multiple sites in all Tsc2ffFoxD1GC mice. Immunohistochemistry staining showed a high expression of phospho-S6-S240/244, a hallmark of activated mTORC1, as well as pericyte markers NG2 and vimentin in these tumors. In summary, we demonstrate that loss of Tsc2 in pericytes generates HPC, the first mouse model of HPC reported.

Histopathological and Immunohistochemical Characteristics of a Local Aggressive Canine Hemangiopericytoma (CHP) after Surgery

Case description: In the present paper, we describe the gross morphology, histopathology and immunoreactivity of a hemangiopericytoma (HP) as a PWT in a dog with recurrence after surgical excision. Clinical findings: The mass was 3-4 cm, solitary, soft, unencapsulated, well circumscribed and grey to brown color. Cut surfaces of the mass contained discrete, round and relatively homogeneous tumors without any lobulation and liquefied foci in the centers. Histologically, the tumor was richly vascularized which arranged in staghorn vessels pattern. The neoplastic cells were uniform in appearance with mild to moderate pleomorphism and had spindle-shaped to oval/round nuclei with vesicular to hyperchromatic chromatin and eosinophilic to the amphophilic cytoplasm with variable amounts of the collagenous stroma. In the immunohistochemical evaluation, proliferating stromal and vascular cells in this tumor demonstrated strong immunoreactivity for vimentin and α-smooth muscle actin. Although, these cells were negative for S100, lysozyme, CD31, and CD34. Treatment and outcome: Regarding to the repeated recurrence of this tumor after surgical excision, amputation of forelimb will probably be performed. Clinical relevance: The present findings show that hemangiopericytoma in dogs can be a locally aggressive behavior with a repeated recurrence that led to the surgical amputation of limbs or even euthanasia of dogs.

The radiation therapy options of intracranial hemangiopericytoma: An overview and update on a rare vascular mesenchymal tumor.

Hemangiopericytoma (HPC) is an extremely rare hypervascular tumor of mesenchymal lineage. It tends to recur and to develop distant metastases even many years after primary surgical resection. The management of recurrent and metastatic disease is not always so well defined. A complete surgical resection does not eliminate the high risk of local recurrences that occur in the central nervous system, often in the same surgical bed. However, treatment with adjuvant radiotherapy even in cases of complete resection remains controversial. Because of its rarity, there is no standard for treatment. We focused on radiotherapy treatment options, analyzing the literature and making a base on conduct further studies to establish the standard radiation dose to be used for locoregional control of such a complex and extremely rare disease and to help specialists to take the most appropriate therapeutic option.

Grading of meningeal solitary fibrous tumors/hemangiopericytomas: analysis of the prognostic value of the Marseille Grading System in a cohort of 132 patients

The finding that meningeal solitary fibrous tumors (SFTs) and meningeal hemangiopericytomas (HPCs) are both characterized by NAB2-STAT6 gene fusion has pushed their inclusion in the WHO 2016 Classification of tumors of the central nervous system (CNS) as different manifestations of the same entity. Given that the clinical behavior of the CNS SFT/HPC spectrum ranges from benign to malignant, it is presently unclear whether the grading criteria are still adequate. Here, we present the results of a study that analyzed the prognostic value of an updated version of the Marseille Grading System (MGS) in a retrospectively assembled cohort of 132 primary meningeal SFTs/HPCs with nuclear overexpression of STAT6. The median patient follow-up was 64 months (range 4-274 months); 73 cases (55%) were MGS I, 50 cases (38%) MGS II and 9 cases (7%) were MGS III. Progression-free survival (PFS) and disease-specific survival (DSS) were investigated using univariate analysis: the prognostic factors for PFS included MGS, extent of surgery, radiotherapy, chemotherapy and mitotic activity ≥5/10 high-power field (HPF). Moreover, MGS, radiotherapy, mitotic activity ≥5/10 HPF, and necrosis were the prognostic factors measured for DSS. In multivariate analysis, extent of surgery, mitotic activity ≥5/10 HPF, MGS I and MGS III were the independent prognostic factors measured for PFS while necrosis, MGS III and radiotherapy were the independent prognostic factors for DSS. In conclusion, our results show that assessing the malignancy risk of SFT/HPC should not rely on one single criterion like mitotic activity. Therefore, MGS is useful as it combines the value of different criteria. In particular, the combination of a high mitotic activity and necrosis (MGS III) indicates a particularly poor prognosis.

Preoperative Assessment of Pathologic Subtypes of Meningioma and Solitary Fibrous Tumor/Hemangiopericytoma Using Dynamic Computed Tomography: A Clinical Research Study

Solitary fibrous tumors (SFTs)/hemangiopericytomas (HPCs) are highly vascularized tumors well known for malignant, invasive, and highly vascular features. To date, several studies have reported the preoperative imaging findings of SFTs/HPCs. In this study, computed tomography (CT) tumor values acquired from dynamic CT scan were selected to determine the tumor pathology of highly vascular tumors, such as SFTs/HPCs. We conducted a retrospective study on patients with pathologically diagnosed meningiomas and SFTs/HPCs who had undergone a dynamic contrast CT scan. We assessed and compared the CT values of these tumors according to the pathology. From a total of 34 patients, 30 patients with meningiomas and 4 patients with HPCs were included. The mean CT values of SFTs/HPCs and angiomatous meningioma were statistically significantly higher than those of the other meningioma subtypes (P= 0.003). We also performed receiver operating characteristic curve analyses to detect an appropriate cutoff point for the CT value to differentiate tumor pathology, and the calculated threshold was 161 Hounsfield units (HU) (sensitivity, 100%; specificity, 75%; area under the curve, 0.87; 95%, CI 0.75-0.99). This study showed that obtaining a CT value is useful in determining highly vascular tumor pathology preoperatively. When considering neurosurgical extra-axial tumor removal, and when the CT value of tumors is >161 HU, then highly vascular tumors such as SFTs/HPCs or angiomatous meningiomas are likely, and this should be considered prior to surgical intervention and for risk assessment.

Spinal Hemangiopericytoma

Introduction: Most hemangiopericytomas (HPC) are located in the musculoskeletal system and the skin, while the location in the central nervous system (CNS) is rare. Objective and Methods: We describe a patient suffering from a spinal extradural huge HPC, with marked spinal cord compression, extending from C6 to T3 level, who was elected to surgery. Results: Patient was submitted to surgery, via a posterior approach, indentifying a huge red-brown firm mass, highly vascular, that was softly dissected from surrounding tissues. Total gross removal was accomplished, with “in-block” resection, preserving neurological function, as shown by somatosensitive evoked potential. Histopathological examination and immunohistochemistry essay were performed confirming the diagnosis of Hemangiopericytoma. Conclusion: Spinal HPCs respond to approximately 8% of all HPC, tend to occur isolated and attached to spinal duramater, and usually present a good surgical cleavage between the tumor and the dura.

Surveillance for metastatic hemangiopericytoma-solitary fibrous tumors-systematic literature review on incidence, predictors and diagnosis of extra-cranial disease.

Intracranial hemangiopericytomas (HPC) and solitary fibrous tumors (SFTs) (HPC-SFT) are rare vascular tumors that resemble meningioma on imaging and predominantly affect young adults. HPC-SFT have a high rate of local recurrence with well-known propensity for extracranial metastases. This provides clinical dilemmas frequently encountered in oncology: (i) How should these patients be monitored long term? (ii) Which primary tumors are more likely to metastasize? This systematic review aims to identify the incidence, common locations and time to presentation of extra-cranial metastases of HPC-SFT. We will assess the effect of primary tumor location, treatment, grade, patient age, gender and effect of local recurrence on rates of extra-cranial metastasis and discuss the ideal techniques by which patients with intracranial HPC-SFT should be monitored for extra-cranial metastases. Using PRISMA guidelines the authors searched Pubmed. Search terms included hemangiopericytoma, HPC, solitary fibrous tumor/ tumour, SFT, HPC-SFT, extra-cranial metastases, metastases, recurrence, monitoring, follow-up. Studies were identified up to 1st February 2018. Reference lists of identified articles were reviewed to detect other relevant citations. Data were extracted using a standard data collection form and results organized into (i) general study/patient characteristics, (ii) location of extra-cranial metastases, (iii) methodsby which metastases were detected and followed up and (iv) characteristics of primary tumors. Seventy-one studies were identified. Mean recorded follow up ranged from 4 to 312months. Mean age at diagnosis was 42.0years. The overall rate of extra-cranial metastasis was 28% (n = 251/904). The minimum time to extracranial metastases was 3months and the maximum time was 372months. In the 71 studies identified, where site of extra-cranial metastasis was specified, there were 347 metastases in 213 patients. The most common sites for metastases were bone (location not specified) (19.6%) followed by lung and pleura (18.4%), liver (17.6%), and vertebrae (14.1%). Extra-cranial metastatic disease is typically diagnosed following symptomatic presentation. There is little documentation of methods used to monitor patients with extra-cranial HPC-SFT and no clear surveillance paradigm observed. Higher primary tumor grade (WHO Grade III) was associated with a 1.88 (p = 0.016) increased risk of extra-cranial metastasis. Location and treatment of primary tumor, local recurrence, patient age and gender were not. Patients with intracranial HPC-SFT require periodic, long term monitoring for extra-cranial metastases. Metastases occur in any age group and can occur early and late. They vary in location and are typically diagnosed following symptomatic presentation. There is no suggested imaging modality for surveillance. Higher grade primary tumors have a greater risk of metastasis. Regular clinical review is essential with early imaging for symptoms of recurrence/metastasis with imaging modality dependent on clinical concern. Quality evidence for an imaging surveillance protocol in this heterogeneous group of patients is lacking. A multicenter study on appropriate surveillance may be of benefit.

Intracranial haemangiopericytoma: a rare case presenting with haemorrhage

Haemangiopericytomas (HPCs) are rare intracranial tumours. Until 1993 HPC was considered as an angioplastic variant of meningioma.1 The recently published WHO classification of central nervous system (CNS) tumours classifies HPCs...

Solitary fibrous tumours and haemangiopericytoma of the meninges. A retrospective study for outcome and prognostic factor assessment

BackgroundTo report on the outcome of patients diagnosed with central nervous system haemangiopericytoma (HPC) or solitary fibrous tumours (SFT) and identify factors that may influence recurrence and survival. Material and methodsBetween January 1977 and December 2016, a retrospective search identified 22 HPCs/SFTs. The patients underwent a total of 40 surgical resections and 63.6% received radiotherapy. Median follow-up was 7.8 years. ResultsSix patients (27.3%) were re-operated for tumour recurrence. At the end of the study, 15 patients (68.2%) had no residual tumour on the last imaging. Surgical recurrence-free survival at 5 years was 77.4%, [95% CI: 60.1–99.8]. None of the investigated variables was associated with recurrence. At the end of the study, 5 patients were deceased (22.7%) and only 10 patients (45.5%) had no residual tumour on the last imaging and were alive. Overall survival at 5 years was 95%, [95% CI: 85.9–100]. None of the investigated variables was associated with overall survival. Patients who received radiotherapy demonstrated neither a reduced risk of surgical recurrence (P=0.378) nor a longer overall survival (P=0.405). ConclusionSFTs/HPCs are associated with a significant risk of recurrence that may reduce the survival. Even if we could not demonstrate their benefit in this limited series, we believe that tailored maximal tumour resection on initial surgery is beneficial and that adjuvant RT is useful for tumours displaying grade II or III, even in case of complete removal.