Intracranial Hemangiopericytoma Research Articles

Management of recurrent giant hemangiopericytoma: illustrative cases.

Hemangiopericytoma (HPC) is a rare malignancy accounting for 0.4% of intracranial tumors. HPCs are characterized by local aggressiveness, high rates of recurrence, and a tendency to metastasize to extracranial sites. These features make management of HPCs challenging, often requiring a combination of radical resection and radiation. Given their rarity, optimal treatment algorithms remain undefined. The authors report a series of four patients who underwent resection of intracranial HPC. Mean age at presentation was 49.3 years. Three patients had reoperation for progression of residual tumor, and one patient was surgically retreated for recurrence. One patient received adjuvant radiotherapy following initial resection, and three patients received adjuvant radiotherapy following resection of recurrent or residual disease. There was one death in the series. Average progression-free survival and overall survival following the index procedure were 32.8 and 82 months, respectively. Progression occurred locally in all patients, with metastatic recurrence in one patient. The current gold-standard treatment for intracranial HPC consists of gross-total resection followed by radiation therapy. This approach allows satisfactory local control; however, given the tendency for these tumors to recur either locally or distally within or outside of the central nervous system, there is a need for salvage therapies to improve long-term outcomes for patients.

Abstract 1108: The impact of adjuvant radiotherapy (ART) and survival prediction by machine learning in intracranial hemangiopericytoma (HPC)

Abstract Background: Intracranial HPC is a rare brain tumor that accounts for less than 1% of all primary central nervous system malignancies. Surgery is the primary treatment, and while radiation may reduce the risk of local recurrence, its overall effectiveness remains uncertain. Therefore, it is crucial to develop reliable predictions for personalized care and improved management. In this study, we used machine learning (ML) techniques to predict the survival of patients with intracranial HPC. Methods: Data were obtained from the Surveillance, Epidemiology, and End Results (SEER) database (2000-2019). Patients with other malignancies or lack of pathological diagnosis were excluded. T-tests and chi-square tests compared variables, while Kaplan-Meier, log-rank tests, and Cox regression identified prognostic factors for overall survival (OS) and cancer-specific survival (CSS). Patient records were randomly divided into training (80 %) and validation (20 %) sets. Univariate Cox regression and least absolute shrinkage and selection operator were used to identify the significant factors linked to survival, which were used to establish a nomogram for predicting the 3- and 5-year OS and CSS. Results: Of the 367 included patients, 121 underwent surgery and 246 underwent surgery + ART. The median survival time was 54 months. Patients who underwent surgery had 5-year OS rates of 61% and 86% for CSS, while those treated with surgery + ART had 81% and 96% survival rates, respectively. The two treatment groups showed significant differences in the OS and CSS (p<0.022 and p<0.017, respectively). Age ≥ 50 years was a poor prognostic factor for OS, whereas ART, localized stage and regional stage were good prognostic factors. No significant factors were associated with CSS. To construct the OS Nomogram, three predictors, age, stage, and treatment method, were chosen. In the training and validation sets, the C-indices are 0.799 and 0.736, respectively. The receiver operating characteristic curves (AUCs) for the 3- and 5-year OS in the training set were 0.594 and 0.617, respectively, whereas those in the validation set were 0.56 and 0.59. For the CSS nomogram, two factors, age and stage, were utilized. The C-indices for the training and validation sets are 0.814 and 0.774, respectively. In the training set, the AUCs for 3- and 5-year CSS were 0.585 and 0.605, respectively, and 0.563 in the validation set. The most important risk factor was the distant stage, while the most important protective factor was age less than 50 years. Conclusion: This study shows that ART has a significant impact on the treatment of Intracranial HPC and provides better survival outcomes. ML has been used to create prediction models to support personalized patient care. These findings provide valuable insights into the management of this rare brain tumor and the potential of data-driven approaches to improve treatment and outcomes. Citation Format: Sakhr Alshwayyat, Anas Alaa Al-Khalili, Ayah Erjan, Haya Kamal, Tala Abdulsalam, Mustafa Alshwayyat. The impact of adjuvant radiotherapy (ART) and survival prediction by machine learning in intracranial hemangiopericytoma (HPC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1108.

Intracranial Hemangiopericytoma- A Case Report

Intracranial hemangiopericytomas are rare vascular tumours, account for less than 1% of all primary tumours of the central nervous system. This tumour usually found outside of CNS i.e., lower extremities and retroperitoneum. Treatment is surgery followed by radiotherapy to decrease chances of recurrences. This is a case report of a young female diagnosed with intracranial hemangiopericytoma in 2021 at our hospital-Acharya Tulsi Regional Cancer Institute, Bikaner.

Intracranial hemangiopericytoma: long-term surgical outcomes

BACKGROUND: According to 2021 WHS Classification, intracranial hemangiopericytomas or solitary fibrous tumors are rare meningeal neoplasms involving blood vessels and soft tissues. Such neoplasms are commonly classified as malignant due to their aggressive growth, metastasizing beyond the cranial cavity, and frequent recurrencies. Since these tumors rarely occur in neurosurgical patients, publications in Russian do not cover big cohorts of patients whose conditions would be assessed during both early and late observation periods.
 AIM: The present study analyzed our experience in surgical treatment of hemangiopericytomas and its long-term results.
 METHODS: The study was arranged as a single-center, pro-and retrospective trial that included hemangiopericytomas patients (n=17), whose tumors of different grades of malignancy (13) were operated at the Federal Neurosurgical Center in Novosibirsk from 2013 to 2021. The follow-up estimates included survivability; physical status (Karnofskys Scale); radicality; metastatic foci; need for postoperative chemo-and radiation therapy; adjuvant therapy effect on patients survivability, and delaying time to relapse.
 RESULTS: In total, 17 patients were included. 11 of them underwent total hemangiopericytomas removal (65%), and 6 subtotal removal (35%). Their survivability within the first year after the operation was 100%. As for the 5-year follow up, only 8 patients out of 17 were available, their mean observation time comprising 64.7 months. The 5-year survivability was 75% (6 out of 8 patients). A relapse occured in 3 out of 17 (17.5%). The mean delaying time comprised 67 months. 6 out of 17 patients (35%) underwent radiation therapy. Among the patients with total and subtotal removals who underwent postoperative radiation treatment neither a relapse nor tumor growth nor metastases were found.
 CONCLUSION: Intracranial hemangiopericytoma is a rare malignant space-occupying neoplasm. Considering our experience and published data, its treatment requires aggressive tactics that includes a radical removal of the tumor followed by early irradiation of the tumors residual volume or bed either in a proton accelerator or a gamma-knife facility notwithstanding its malignancy grade. It is also recommended to extend the follow-up period for such patients to 1015 years that should include annual cancer screening to detect local relapses and metastases.

OR27-5 Malignancies in Prader-Willi Syndrome: Practical Recommendations Based on a Large International Cohort

Abstract Introduction Prader-Willi syndrome (PWS) is a complex disorder combining hypothalamic dysfunction, pituitary hormone deficiencies, neurodevelopmental delay, high pain threshold, hypotonia and hyperphagia with risk of obesity and its complications. PWS is caused by the loss of expression of a cluster of paternally expressed genes on chromosome 15q11.2-q13 called the PWS critical region, mostly due to paternal deletion (DEL) or maternal uniparental disomy. As life expectancy of patients with PWS increases, age-related diseases like malignancies might pose a new threat to health. Multiple genes in the PWS critical region have been associated with the development of malignancies and obesity is a risk factor for many types of malignancies. The aim of this study was to investigate the prevalence and pathogenesis of malignancies and to provide clinical recommendations for screening in patients with PWS. Methods We collected information on a (for rare disorders) exceptionally large cohort of 706 patients with PWS (160 children, 546 adults). All patients had visited the seven participating centers in Europe and Australia. Data was collected retrospectively from medical records on past or current malignancies, the type of malignancy and risk factors for malignancies. Genotype, age, gender, body mass index (BMI), tobacco use, presence of type 2 diabetes mellitus, growth hormone treatment and sex hormone replacement therapy were assessed in relation to the occurrence of malignancies. Additionally, we systematically searched the literature for information about the relationship between genes in the PWS critical region and malignancies. Results Seven adults (age range 18-55 years old) had been diagnosed with malignancies (acute lymphoblastic leukemia, intracranial hemangiopericytoma, melanoma, adenocarcinoma of the stomach, cholangiocarcinoma, parotid adenocarcinoma and colorectal carcinoma). Genetic subtype was DEL for 100% of the patients with malignancies, compared to 58% in patients without a malignancy (p=0.045). Age, gender, BMI, tobacco use, type 2 diabetes mellitus, growth hormone treatment and sex hormone replacement were not significantly related to the presence of malignancies. Conclusion In conclusion, malignancies are rare in patients with PWS. Remarkably, patients with the DEL genetic subtype have a significantly higher risk of developing malignancies compared to patients with other genotypes. Although malignancies are rare in PWS, participation in regular national screening programs for cervical, breast and colon cancer is important as the high pain threshold and intellectual disability make presentation of physical complaints less reliable. We recommend to perform additional diagnostic testing in case of symptoms suggestive of paraneoplastic syndrome, localizing symptoms, loss of appetite or unexplained weight loss. Presentation: Tuesday, June 14, 2022 10:45 a.m. - 11:00 a.m.

A Rare Cause of Severe Hypoglycemia in Intracranial Hemangiopericytoma Associated With Non-Islet Cell Tumor Hypoglycemia

A 60-year-old man with a history of metastatic intracranial hemangiopericytoma and type 2 diabetes mellitus presented with acute episodes of confusion and dizziness. A magnetic resonance imaging scan of the brain showed progressing calvarial metastasis without intracranial abnormality. He was found to have severe persistent hypoglycemia. The initial hypoglycemia work-up revealed low serum insulin and C-peptide level and negative panel for oral hypoglycemic agents. Further laboratory testing revealed an elevated insulin-like growth factor II (IGF II):IGF-I ratio and low β-hydroxybutyrate, consistent with nonislet cell tumor hypoglycemia. The patient received prednisone and his hypoglycemia improved.

Sixteen-Year Follow-Up in a Cavernous Sinus Hemangiopericytoma: Improved Outcomes over Radiotherapy Advances

Intracranial hemangiopericytomas are rare tumors, accounting for 1% of all central nervous system malignancies. This tumor is considered at high risk of local and also distant metastases. Surgical excision is the gold standard for treatment, but it is seldom curative by itself. Adjuvant radiotherapy is often recommended. We report an overview and update of the available literature on one such rare but aggressive mesenchymal tumor, using the case of a 46-year-old woman affected by hemangiopericytoma of the cavernous sinus surgically removed and treated with adjuvant radiotherapy at our institution. After seven years, the patient underwent a local recurrence and was treated with exeresis and Gamma Knife radiotherapy. Sixteen years after the initial diagnosis, she is still well with stable disease.

The significant role of multimodality imaging with 18Fluorocholine PET/CT in relapsed intracranial hemangiopericytoma

The significant role of multimodality imaging with 18Fluorocholine PET/CT in relapsed intracranial hemangiopericytoma

Clinical Profile and Outcomes of Primary Immunodeficiency and Malignancy in Childhood at a Tertiary Oncology Center in Developing Country

Primary immune deficiencies are a group of heterogenous genetic disorders characterized by frequent infections, autoimmunity and malignancy. In this study, we aimed to evaluate clinical characteristics, outcomes of children with malignancy developed on background of primary immunodeficiency and compare survival rates of patients between malignant lymphoma with primary immunodeficiency and without immunodeficiency from tertiary oncology center in a developing country. A total 23 patients with primary immunodeficiency and malignancy were evaluated retrospectively. A total of 26 malignancies (first or second) in 23 patients were determined. The median age at the time of the first malignancy was 8 years (ranges 2–18 years) with increased male ratio (M/F:14/9). Non-Hodgkin lymphoma (n = 17; 65%) was the most common malignancy, followed by Hodgkin lymphoma (n = 5), anaplastic ependymoma (n = 1), spinal glioblastoma multiforme (n = 1), retinoblastoma (n = 1) and intracranial hemangiopericytoma (n = 1). The median follow-up time of patients was 25 months (ranges between 1 and 189 months). The 5-year overall survival rate of patients with malignant lymphoma associated with primary immunodeficiency (41%) were lower than immunocompetent patients with malignant lymphoma (80%) (p = 0.000). The 5-year overall survival of patients was diagnosed between 2021 and 2013 years (62%) was higher than previous years (22%) (p = 0.03). In conclusion, non-Hodgkin lymphomas were the most common histopathologic type in patients with malignancy associated with primary immunodeficiency in the present study. The survival of patients with malignant lymphoma associated with primary immunodeficiency has improved in recent years, yet it is still lower than immunocompetent patients with lymphoma and new targeted drugs are required for better survival rates.

Non-Invasive Preoperative Imaging Differential Diagnosis of Intracranial Hemangiopericytoma and Angiomatous Meningioma: A Novel Developed and Validated Multiparametric MRI-Based Clini-Radiomic Model.

BackgroundAccurate preoperative differentiation of intracranial hemangiopericytoma and angiomatous meningioma can greatly assist operation plan making and prognosis prediction. In this study, a clini-radiomic model combining radiomic and clinical features was used to distinguish intracranial hemangiopericytoma and hemangioma meningioma preoperatively.MethodsA total of 147 patients with intracranial hemangiopericytoma and 73 patients with angiomatous meningioma from the Tiantan Hospital were retrospectively reviewed and randomly assigned to training and validation sets. Radiomic features were extracted from MR images, the elastic net and recursive feature elimination algorithms were applied to select radiomic features for constructing a fusion radiomic model. Subsequently, multivariable logistic regression analysis was used to construct a clinical model, then a clini-radiomic model incorporating the fusion radiomic model and clinical features was constructed for individual predictions. The calibration, discriminating capacity, and clinical usefulness were also evaluated.ResultsSix significant radiomic features were selected to construct a fusion radiomic model that achieved an area under the curve (AUC) value of 0.900 and 0.900 in the training and validation sets, respectively. A clini-radiomic model that incorporated the radiomic model and clinical features was constructed and showed good discrimination and calibration, with an AUC of 0.920 in the training set and 0.910 in the validation set. The analysis of the decision curve showed that the fusion radiomic model and clini-radiomic model were clinically useful.ConclusionsOur clini-radiomic model showed great performance and high sensitivity in the differential diagnosis of intracranial hemangiopericytoma and angiomatous meningioma, and could contribute to non-invasive development of individualized diagnosis and treatment for these patients.

Intracranial hemangiopericytoma with right-sided aortic arch: a case report and summary of experience

Intracranial hemangiopericytoma with right-sided aortic arch: a case report and summary of experience

INNV-24. METASTATIC HEMANGIOPERICYTOMA TO THE LIVER: DEFINING THE IMPORTANCE OF NAB-STAT2 FUSION

Abstract BACKGROUND Meningeal hemangiopericytoma (HPC) is a rare and aggressive vascular tumor which typically occurs in younger adults and has a tendency for local recurrence with delayed metastases outside the CNS. HPC is considered a variant of solitary fibrous tumor (SFT), and is associated with the presence of the fusion oncoprotein NAB2-STAT6. This fusion results in over-expression of the EGR1 gene and results in tumorigenesis. CASE REPORT We present a case of a 49 y/o female with a remote history of left occipital lobe HPC, initially treated with resection and radiotherapy in 2007, who presented with symptoms of right upper quadrant abdominal pain. She was found to have a hypervascular 7 cm mass in the right upper lobe of the liver on magnetic resonance imaging (MRI) studies and subsequently underwent hepatectomy for removal of the mass. Histopathological findings revealed metastatic HPC with features consistent with her primary meningeal tumor that was removed over 13 years agoearlier. Presence of the NAB2-STAT6 fusion was confirmed by targeted genomic analysis. MRI revealed a small focus of nodular enhancement abutting the confluence of the superior sagittal sinus and transverse sinus. This was considered her source of disease and possible dissemination. She was treated with stereotactic radiosurgery to target the lesion. DISCUSSION Given the rarity and often remote medical history of the primary intracranial HPC, this report suggests that 1) long term follow up of HPC is essential and 2) detection of the NAB2-STAT6 fusion can identify and confirm recurrent HPC at metastatic sites. In regards to the latter, distinguishing HPCs from other more benign spindle cell tumors that may mimic SFT (such as fibroblastic meningiomas) is also of therapeutic significance as HPCs typically require adjuvant treatment, (i.e. radiotherapy) as opposed to surgical resection alone.

Does post-operative radiotherapy improve the treatment outcomes of intracranial hemangiopericytoma? A retrospective study

BackgroundIntracranial hemangiopericytoma is a rare disease and surgery is the mainstay treatment. Although postoperative adjuvant radiotherapy is often used, there are no reports comparing different radiotherapy techniques. The purpose of this study is to analyze the impact of post-operative radiotherapy and different radiotherapy technique on the results in patients with intracranial hemangiopericytoma (HPC).MethodsWe retrospectively reviewed 66 intracranial HPC patients treated between 1999 and 2019 including 29 with surgery followed by radiotherapy (11 with intensity-modulated radiotherapy (IMRT) and 18 with stereotactic radiosurgery (SRS)) and 37 with surgery alone. Chi-square test was used to compare the clinical characteristic between the groups. The Kaplan-Meier method was used to analyze overall survival (OS) and recurrence-free survival (RFS). Multivariate Cox proportional hazards models were used to examine prognostic factors of survival. We also underwent a matched-pair analysis by using the propensity score method.ResultsThe crude local control rates were 58.6% in the surgery plus post-operative radiotherapy group (PORT) and 67.6% in the surgery alone group (p = 0.453). In the subgroup analysis of the PORT patients, local controls were 72.7% in the IMRT group and 50% in the SRS group (p = 0.228). The median OS in the PORT and surgery groups were 122 months and 98 months, respectively (p = 0.169). The median RFS was 96 months in the PORT group and 72 months in the surgery alone group (p = 0.714). Regarding radiotherapy technique, the median OS and RFS of the SRS group were not significantly different from those in the IMRT group (p = 0.256, 0.960). The median RFS were 112 and 72 months for pathology grade II and III patients, respectively (p = 0.001). Propensity score matching did not change the observed results.ConclusionIn this retrospective analysis, PORT did not improve the local control rates nor the survivals. The local control rates after IMRT and SRS were similar even though the IMRT technique had a much higher biological dose compared with the SRS technique.

Treatment of Residual, Recurrent, or Metastatic Intracranial Hemangiopericytomas With Stereotactic Radiotherapy Using CyberKnife.

PurposeHemangiopericytomas are aggressive tumors known for their recurrence. The purpose of this study was to evaluate the management of residual, recurrent, and metastatic intracranial hemangiopericytomas using CyberKnife (CK) stereotactic radiotherapy (SRT).Materials and MethodsData were collected from 15 patients (28 tumors; eight men and seven women; 32–58 years) with residual, recurrent, or metastatic intracranial hemangiopericytomas, who were treated with stereotactic radiotherapy using CyberKnife between January 2014 and August 2019. All patients had previously been treated with surgical resection. Initial tumor volumes ranged from 0.84 to 67.2 cm3, with a mean volume of 13.06 cm3. The mean marginal and maximum radiosurgical doses to the tumors were 21.1 and 28.76 Gy, respectively. The mean follow-up time for tumors was 34.5 months, ranging from 13 to 77 months.Results15 patients were alive after treatment; the mean post-diagnosis survival at censoring was 45.6 months (range 13–77 months). The volumes of the 28 tumors in the 15 followed patients were calculated after treatment. Postoperative magnetic resonance imaging revealed a mean tumor volume of 6.72 cm3 and a range of 0–67.2 cm3, with the volumes being significantly lower than pretreatment values. Follow-up imaging studies demonstrated tumor disappearance in seven (25%) of 28 tumors, reduction in 14 (50%), stability in one (3.57%), and recurrence in six (21.4%). Total tumor control was achieved in 22 (78.5%) of 28 tumors. The tumor grade and fraction time were not significantly associated with progression-free survival. Intracranial metastasis occurred in three patients, and extraneural metastasis in one patient.ConclusionsOn the basis of the current results, stereotactic radiotherapy using CyberKnife is an effective and safe option for residual, recurrent, and metastatic intracranial hemangiopericytomas. Long-term close clinical and imaging follow-up is also necessary.

Intracranial Hemangiopericytoma – A Case Report

Hemangiopericytoma is a rare mesenchymal tumor, considered as a subtype of soft tissue sarcomas with an incidence of 3.77/10.000.000 cases. Intracranial hemangiopericytomas account for less than 1% of all primary tumors of the central nervous system. Due to the lack of data available regarding this disease, national and international research provides information derived from retrospective case series and phase I and phase II studies. This is a case report of a young adult diagnosed with intracranial hemangiopericytoma in 2012 with a history of multiple recurrences and therapeutic approaches, assisted in a public health center in southeastern Brazil. Among the treatment options given to the patient, there are surgery, radiotherapy, and systemic chemotherapy (including alkylating and anthracyclines agents). Systemic therapy usually is offered after multiple recurrences or in a metastatic setting; although it increases progression-free survival, there is not enough data on objective response rate and does not yield increased overall survival.

Results in the treatment of intracranial haemangiopericytomas. Case series

ObjectiveIntracranial hemangiopericytoma (HPC) is a rare central nervous system tumor characterized by its low incidence, high rate of local recurrence and risk of metastasis. The main objectives of this paper are two: to show the results in the treatment of HPC in our institution in the last 20 years and to make a review of the literature on this topic. MethodsRetrospective review that includes patients diagnosed with intracranial solitary fibrous tumor/hemangiopericytoma (TFS/HPC) that have undergone surgery from 1997 to 2017. It includes patients that had nuclear expression of STAT6 (detected by immunohistochemistry) and grade II/III histopathological diagnosis (defined by the World Health Organization in 2016). We collected demographic data, tumor characteristics, treatment and survival of these patients. ResultsA total of 19 patients fulfilled inclusion criteria. The median follow up was 96 months (12–230). The mortality rate was 21% (n = 4). The median follow up survival was 19.16 years. 57.9% of patients presented at least 1 tumor recurrence (n = 11) (recurrences of 6%, 67% y 90% at 1, 5 and 10 years). Five patients presented extracranial metastasis. Patients with tumors <6 cm had greater survival (p < 0.05). ConclusionsA series of patients undergoing TFS / HPC were presented according to the new WHO criteria. Size is a predictor of survival. Currently there are no validated criteria for surgical resection in this pathology. A classification with surgical guidance would be useful.

Results in the treatment of intracranial hemangiopericytomas. Case series.

Intracranial hemangiopericytoma (HPC) is a rare central nervous system tumor characterized by its low incidence, high rate of local recurrence and risk of metastasis. The main objectives of this paper are two: to show the results in the treatment of HPC in our institution in the last 20years and to make a review of the literature on this topic. Retrospective review that includes patients diagnosed with intracranial solitary fibrous tumor/hemangiopericytoma (SFT/HPC) that have undergone surgery from 1997 to 2017. It includes patients that had nuclear expression of STAT-6 (detected by immunohistochemistry) and gradeII/III histopathological diagnosis (defined by the World Health Organization in 2016). We collected demographic data, tumor characteristics, treatment and survival of these patients. A total of 19 patients fulfilled inclusion criteria. The median follow up was 96 months (12-230). The mortality rate was 21% (n=4). 57.9% of patients presented at least one tumor recurrence (n=11) (recurrences of 6%, 67% y 90% at 1, 5 and 10years). Five patients presented extracranial metastasis. Patients with tumors <6cm had greater survival (P<.05). A series of patients undergoing SFT/HPC were presented according to the new WHO criteria. Size is a predictor of survival. Currently there are no validated criteria for surgical resection in this pathology. A classification with surgical guidance would be useful.

Accurate Preoperative Distinction of Intracranial Hemangiopericytoma From Meningioma Using a Multihabitat and Multisequence-Based Radiomics Diagnostic Technique.

Background: Intracranial hemangiopericytoma (IHPC) and meningioma are both meningeal neoplasms, but they have extremely different malignancy and outcomes. Because of their similar radiological characteristics, they are difficult to distinguish prior to surgery, leading to a high rate of misdiagnosis.Methods: We enrolled 292 patients (IHPC, 155; meningiomas, 137) with complete clinic-radiological and histopathological data, from a 10-year database established at Tiantan hospital. Radiomics analysis of tumor and peritumoral edema was performed on multisequence magnetic resonance images, and a fusion radiomics signature was generated using a machine-learning strategy. By combining clinic-radiological data with the fusion radiomics signature, we developed an integrated diagnostic approach that we named the IHPC and Meningioma Diagnostic Tool (HMDT).Results: The HMDT displayed remarkable diagnostic ability, with areas under the curve (AUCs) of 0.985 and 0.917 in the training and validation cohorts, respectively. The calibration curve showed excellent agreement between the diagnosis predicted by HMDT and the histological outcome, with p-values of 0.801 and 0.622 for the training and the validation cohorts, respectively. Cross-validation showed no statistical difference across three divisions of the cohort, with average AUCs of 0.980 and 0.941 for the training and validation cohorts, respectively. Stratification analysis showed consistent performance of the HMDT in distinguishing IHPC from highly misdiagnosed subgroups of grade I meningioma and angiomatous meningioma (AM) with AUCs of 0.913 and 0.914 in the validation cohorts for the two subgroups.Conclusions: By integrating clinic-radiological information with radiomics signature, the proposed HMDT could assist in preoperative diagnosis to distinguish IHPC from meningioma, providing the basis for strategic decisions regarding surgery.

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

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

A Case of Surgical Resection of Metastatic Pancreatic Tumors from an Intracranial Hemangiopericytoma

症例は51歳，女性．頭蓋内hemangiopericytoma（以下，頭蓋内HPC）に対して，開頭腫瘍摘出術を施行し，その10年後の腹部造影CTで，膵頭部および膵尾部に造影効果を有する腫瘍を認めた．頭蓋内HPCの転移性膵腫瘍が疑われたが，膵神経内分泌腫瘍の可能性も考えられたため，膵尾部の腫瘍に対して超音波内視鏡下穿刺吸引を施行した．その結果，頭蓋内HPCの転移性膵腫瘍の診断となった．膵頭部，膵尾部の病変に対して，亜全胃温存膵頭十二指腸切除術および，尾側膵切除術を施行した．病理組織学的には，これらの病変の組織像が頭蓋内HPCに類似しており，HPCに特徴的なSTAT6の核内陽性像を認めたため，膵頭部・膵尾部の病変はともに頭蓋内HPCの転移性膵腫瘍の診断となった．