Recurrent Intracranial Hemangiopericytoma with Extracranial and Unusual Multiple Metastases: Case Report and Review of the Literature

Multidisciplinary Treatment of Liver Metastases from Intracranial SFTs/HPCs: A Report of Three Consecutive Cases

In the 2016 WHO classification of tumors of the central nervous system, hemangiopericytomas (HPCs) and solitary fibrous tumors (SFTs) were integrated into a new entity (SFT/HPC). Metastases to bone, liver, lung, and abdominal cavity are of concern. Only 37 cases of patients with liver metastases due to intracranial SFTs/HPCs have been reported. Herein, we present our experience in the management of patients with liver metastases from intracranial SFTs/HCPs. All consecutive patients who were treated for liver metastases from intracranial SFTs/HPCs from January 2014 to December 2020 were enrolled. Overall, three patients were treated for liver metastasis from SFTs/HPCs with curative intent. Two patients with bilobar metastases at presentation required surgical resection, transarterial embolization, stereotactic radiofrequency ablation (SRFA) and systemic therapy. One patient with a singular right liver lobe metastasis was treated with SRFA alone. This patient shows no evidence of liver metastases 39 months following diagnosis. Of the two patients with bilobar disease, one died 89 months following diagnosis, while one is still alive 73 months following diagnosis. Long-term survival can be achieved using a multimodal treatment concept, including surgery, loco-regional and systemic therapies. Referral to a specialized tertiary cancer center and comprehensive long-term follow-up examinations are essential.

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.

Intracranial solitary fibrous tumor/hemangiopericytoma mimicking cystic meningioma: A case report and literature review

Intracranial solitary fibrous tumor/hemangiopericytoma (SFT/HPC) is a relatively rare type of tumor that originates from meningeal mesenchyme. A 30-year-old man presented leaning his body to the left and with weakness of his left lower limb. Computed tomography revealed a heterogeneous mass with multiple cystic components and hyperostosis of the right cranial convexity. Magnetic resonance imaging showed the mass was broadly attached to the dura matter with dural tail sign. In addition, the lesion had extensive cystic degeneration and a solid compartment showing low apparent diffusion coefficient values. The patient underwent gross total resection of the intracranial lesion and presented no recurrence within a 12-month follow-up period. Histopathology confirmed SFT/HPC (World Health Organization grade Ⅱ). Although there have been several useful techniques reported to differentiate SFT/HPC from meningioma, in this case the atypical findings for SFT/HPC made it difficult. We report the imaging findings of this case and some literature reviews.

Hepatic metastasis from a meningeal hemangiopericytoma: A case report

INTRODUCTION

A meningeal hemangiopericytoma (MHPC) is an aggressive tumor characterized by a high rate of local recurrence and late distant metastasis. The objective of this study was to share our experience with the treatment of a MHPC and how to distinguish this tumor from a meningioma.

PATIENT CONCERNS

A 62-year-old woman presented with symptoms of hypomnesia, hyperopia, and double vision for 1 month. Complete tumor excision was performed 6 years before. A biopsy sample was diagnosed as an atypical meningioma.

DIAGNOSIS

MHPC with late delayed hepatic metastasis.

INTERVENTION

Hepatic resection was performed initially, followed by secondary neurosurgery for complete excision of the bilateral frontal lesion 1 month later.

OUTCOME

Based on the tumor pathology and consensus of oncologic surgeons, radiation therapy was initiated. Adjuvant therapy was well-tolerated and the patient remained recurrence-free at 6 months after surgery.

CONCLUSION

Here, we report a case of local brain tumor recurrence and multiple hepatic metastases from a MHPC. Craniotomy combined with radical metastasectomy may be useful in such cases. Detailed immunohistochemical staining is helpful to distinguish a MHPC from a meningioma. Long-term follow-up is recommended.

Extensive systemic metastases from primary central nervous system haemangiopericytoma

Primary intracranial tumours rarely metastasise outside of the central nervous system (CNS). This report describes a rare case of recurrent meningeal haemangiopericytoma with extensive systemic metastases, which eventually resulted in a fatal outcome. We discuss some prevailing theories as to the rarity of extracranial metastases from primary CNS haemangiopericytoma, and elucidate the epidemiology, imaging features, differential diagnosis, treatment, and prognosis of this unusual but surprisingly aggressive meningeal tumour. Besides aggressive treatment for local tumour control, patients with primary CNS haemangiopericytoma require long-term post-treatment surveillance to detect systemic metastases.

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

Background:

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

Case Description:

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

Conclusion:

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

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

BACKGROUND

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?

OBJECTIVES

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.

METHODS

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) methods by which metastases were detected and followed up and (iv) characteristics of primary tumors.

RESULTS

Seventy-one studies were identified. Mean recorded follow up ranged from 4 to 312 months. Mean age at diagnosis was 42.0 years. The overall rate of extra-cranial metastasis was 28% (n = 251/904). The minimum time to extracranial metastases was 3 months and the maximum time was 372 months. 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.

CONCLUSION

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.

Magnetic resonance imaging of intracranial hemangiopericytoma and correlation with pathological findings

The present study aimed to evaluate the radiological and pathological features of intracranial hemangiopericytoma, and improve the understanding of this tumor. A retrospective analysis of radiological and pathological features of five cases of intracranial hemangiopericytoma was conducted between 2006 and 2012 in the Second Xiangya Hospital of Central South University. A total of five cases (three males and two females; aged 37–60 years) were enrolled. Magnetic resonance imaging revealed that the lesions were lobulated with iso-intensity T1-weighted image signals and slightly long T2-weighted image signals. Cystic degeneration, necrosis and flow void were observed. The case with the lesion located under the tentorium cerebelli exhibited compression of the fourth ventricle with lateral ventricle dilatation hydrocephalus. In all cases, the solid section of the lesion was markedly enhanced following injection of the contrast agent, and intratumoral vessels were observed. No case exhibited the dural tail sign. Immunohistochemical examination revealed positive expression of cluster of differentiation 34(CD34), vimentin and CD99, and negative expression of epithelial membrane antigen, S100 and glial fibrillary acidic protein. Proliferating cell nuclear antigen Ki-67 immunohistochemical staining revealed that <5% of cells expressed Ki-67 in two cases and 5–10% of cells expressed Ki-67 in three cases. In conclusion, intracranial hemangiopericytoma exhibits certain distinctive characteristics in radiological examination, allowing for improved diagnosis. However, pathological examination is required for confirmation.

The role for adjuvant radiotherapy in the treatment of hemangiopericytoma: a Surveillance, Epidemiology, and End Results analysis

Object

Central nervous system (CNS) hemangiopericytomas are relatively uncommon and unique among CNS tumors as they can originate from or develop metastases outside of the CNS. Significant difference of opinion exists in the management of these lesions, as current treatment paradigms are based on limited clinical experience and single-institution series. Given these limitations and the absence of prospective clinical trials within the literature, nationwide registries have the potential to provide unique insight into the efficacy of various therapies.

Methods

The authors queried the Surveillance Epidemiology and End Results (SEER) database to investigate the clinical behavior and prognostic factors for hemangiopericytomas originating within the CNS during the years 2000–2009. The SEER survival data were adjusted for demographic factors including age, sex, and race. Univariate and multivariate analyses were performed to identify characteristics associated with overall survival.

Results

The authors identified 227 patients with a diagnosis of CNS hemangiopericytoma. The median length of follow-up was 34 months (interquartile range 11–63 months). Median survival was not reached, but the 5-year survival rate was 83%. Univariate analysis showed that age and radiation therapy were significantly associated with survival. Moreover, young age and supratentorial location were significantly associated with survival on multivariate analysis. Most importantly, multivariate analysis using the Cox proportional hazards model showed a statistically significant survival benefit for patients treated with gross-total resection (GTR) in combination with adjuvant radiation treatment (HR 0.31 [95% CI 0.01–0.95], p = 0.04), an effect not appreciated with GTR alone.

Conclusions

The authors describe the epidemiology of CNS hemangiopericytomas in a large, national cancer database, evaluating the effectiveness of various treatment paradigms used in clinical practice. In this study, an overall survival benefit was found when GTR was accomplished and combined with radiation therapy. This finding has not been appreciated in previous series of patients with CNS hemangiopericytoma and warrants future investigations into the role of upfront adjuvant radiation therapy.

Hemangiopericytoma of the posterior fossa: a case report and review of the literature

Intracranial hemangiopericytoma is unusual, and those occurring in the posterior fossa is extremely rare; we report such a rare case of hemangiopericytoma of the posterior fossa. The radiologic findings and gross characteristics of hemangiopericytomas are sometimes quite similar to those of meningiomas. Although extremely rare, the operator should be aware of the existence of this disorder to dexterously manage the aggressive nature and high vascular tendency of hemangiopericytomas. The radiological features and histological findings in this case are discussed in this study.

Haemangiopericytoma presenting with acute intracerebral haemorrhage--a case report and literature review

BACKGROUND

Intracranial haemangiopericytoma (HPC), a rare malignant tumour, should be distinguished from meningioma and solitary fibrous tumour, which have been considered as separate entities since 1993, according to histopathology and clinical characteristics.

METHODS

A PUBMED search for "Intracranial Haemangiopericytoma" yielded 176 articles, where 26 were of particular interest for this review article.

CASE REPORT

Our patient, a 27-year-old man with HPC of grade III according to WHO, presents with an acute intracerebral haematoma, which is extremely rare.

RESULTS

Surgery (total resection) is the primary treatment. Long-term close clinical and radiological follow-up is crucial due to the high rate of recurrence and tendency for development of metastasis.

DISCUSSION

The effects of postoperative radiotherapy need further investigation. Besides neurosurgery, radiotherapy should always be considered in both patients with these highly malignant tumours (WHO grade III) and in patients with partial resection or inoperable cases (WHO grade II).

Intracranial meningeal hemangiopericytoma: 10 years experience of a tertiary care Institute

BACKGROUND

Intracranial meningeal hemangiopericytoma (HPC) represents a rare and aggressive intracranial neoplasm located along the dural sinuses. It constitutes less than 1 % of all intracranial tumors and approximately 2-4 % of all meningeal tumors. The authors present our institute's experience in combined modality management of 15 successive patients of HPC.

METHODS

We retrospectively reviewed 15 patients of HPC treated in our institute from 2001 to 2011. Clinical characteristics and treatment modality, in the form of surgery and radiotherapy, were noted. Statistical analysis was done with regards to recurrence free survival (RFS) and overall survival (OS) using Kaplan-Meier survival analysis.

RESULTS

The median age of the patients was 40.0 years. Nine patients were males and six patients were females. The median duration of symptoms was six months. Headache was the most common presenting symptom followed by vomiting, motor weakness and seizures. Twelve patients underwent total excision while three had subtotal excision. Seven patients had WHO grade II histology tumors and eight patients had grade III histology. Thirteen patients received adjuvant radiotherapy (RT). Median RT dose delivered was 50 Gy. Five patients developed local recurrence. One patient had distant metastases. Median duration of RFS was 68 months.

CONCLUSIONS

HPCs are aggressive tumors. The mainstay of therapy is gross total resection at the initial surgery. Postoperative adjuvant RT should be offered to all patients, regardless of the degree of resection achieved. Long-term follow-up is important as local recurrences and distant metastases can develop years after the initial treatment.

Incidental meningiomas

With the increasing availability and use of modern brain diagnostic imaging modalities, discovery of incidental meningiomas has become fairly common. This creates a dilemma among neurosurgeons as to whether these lesions should be treated. Numerous natural history studies have been published in an effort to shed light on the potential for growth of incidental meningiomas. The available data appear to suggest that these tumors can fall into 1 of 3 main growth patterns: no growth, linear growth, or exponential growth. The therapeutic strategy selected should also consider several other factors, mainly the risk of complications from an eventual surgery, the possibility of malignancies and other pathological conditions that mimic meningiomas, and the age and medical condition of the patient. The authors believe that most asymptomatic incidental meningiomas can be observed using serial imaging and clinical follow-up evaluations. Surgical interventions are typically reserved for large, symptomatic lesions and those with documented potential for significant growth.

Thirty-nine cases of intracranial hemangiopericytoma and anaplastic hemangiopericytoma: a retrospective review of MRI features and pathological findings

OBJECTIVE

To retrospectively review the imaging features of surgically and pathologically confirmed intracranial hemangiopericytoma and anaplastic hemangiopericytoma.

METHODS

Thirty-nine cases of surgically and pathologically confirmed hemangiopericytoma and anaplastic hemangiopericytoma were analyzed retrospectively. The MRI features were compared with pathological findings in all cases.

RESULTS

Of the 39 cases, 21 were anaplastic hemangiopericytoma (WHO grade III) and the remaining cases were hemangiopericytoma (WHO grade II); all lesions were solitary. MRI of anaplastic hemangiopericytoma showed that 20 cases were lobulated, and nine grew cross-leaf. The lesions showed mixed iso-high-low signal (n=20) or iso-signal (n=1) on plain T1WI, and mixed high-low signal (n=20) or iso-signal (n=1) on plain T2WI. After contrast injection, marked heterogeneous enhancement was seen in 19 cases. Significant necrosis and cystic changes were seen in 16 cases, and the "dural tail sign" was found in two cases. Ten cases had bony destruction, and 16 showed significant peritumoral edema. In 18 cases of hemangiopericytoma, nine were oval-shaped and three grew cross-leaf. The lesions showed mixed iso-low signal (n=10) or iso-signal (n=8) on plain T1WI, and mixed iso-high signal (n=10) or iso-signal (n=8) on plain T2WI. After contrast injection, significant uniform enhancement was seen in 10 cases. Significant necrosis and cystic changes were seen in seven cases, and "dural tail sign" was seen in six cases. Two cases had bony destruction. No case showed significant peritumoral edema. Pathological immunohistochemical Ki67 staining showed a concentration of ∼18.4% positive cells in anaplastic hemangiopericytoma, whereas in hemangiopericytoma it was 7.12%.

CONCLUSION

Imaging findings of intracranial anaplastic hemangiopericytoma had more pronounced lobulation, cross-leaf growth tendency, more and easier bleeding, more necrosis, more cystic changes giving rise to heterogeneous signals, rarer frequency of the "dural tail sign", more damage near the skull, and more significant peritumoral edema than hemangiopericytoma. These features may help differentiate these two types of malignancy.

Intracranial hemangiopericytoma: clinical experience and treatment considerations in a modern series of 40 adult patients

INTRODUCTION

Intracranial hemangiopericytoma (HPC) is a malignant meningothelial tumor. Because of its rarity, few guidelines exist for optimal management.

METHODS

University of California at San Francisco patients managed for intracranial HPC were compiled into a single database based on a retrospective review of patient records. Univariate and multivariate regression was performed to determine factors that independently predicted treatment outcomes.

RESULTS

A total of 40 patients with intracranial HPC were treated from 1989 to 2010. Treatment and follow-up information was available for analysis on 35 patients. The median survival for all patients was 16.2 years after date of diagnosis, with 1-year, 5-year, and 10-year survival rates of 100%, 92%, and 68%, respectively. Nineteen patients (54%) had HPC recurrence. The median time until recurrence was 5 years, with 1-year, 5-year, and 10-year progression-free survival rates of 96%, 49%, and 28%, respectively. Seven patients (20%) developed extracranial metastasis. Tumor characteristics associated with earlier recurrence included size ≥6 cm (log-rank, P < .05) and nonskull base location (log-rank, P < .05). Strategies combining adjuvant radiation with tumor resection appeared to hinder tumor progression, but had no effect on overall survival or the development of metastasis. Greater extent of resection was associated with increased overall survival (log-rank, P < .05).

CONCLUSIONS

Adjuvant radiation may show promise in preventing tumor progression, but recurrence remains a common treatment outcome regardless of initial strategy. When safe and feasible, gross total resection should be pursued as an initial surgical strategy to maximize overall survival. The propensity of these tumors to metastasize makes detailed staging imaging necessary.

18F-FDG-PET-CT imaging findings of recurrent intracranial haemangiopericytoma with distant metastases

A 42-year-old woman presented with local recurrence and distant lung and liver metastases 7 years after resection of a primary intracranial haemangiopericytoma. Whole-body (18)F-fluoro-2-deoxy-d-glucose (FDG)-positron emission tomography (PET)-CT scan showed no increased uptake in local recurrence or distant metastases except for a focus of increased FDG uptake within a hepatic metastasis. The hypermetabolic area correlated with an intratumoral hypoenhancing area on the CT scan. PET-CT scan may be useful to allow further understanding of the tumour.

Predictors of mortality following treatment of intracranial hemangiopericytoma

OBJECT

Intracranial hemangiopericytoma (HPC) is a rare and malignant extraaxial tumor with a high proclivity toward recurrence and metastasis. Given this lesion's rarity, little information exists on prognostic factors influencing mortality rates following treatment with surgery or radiation or both. A systematic review of the published literature was performed to ascertain predictors of death following treatment for intracranial HPC.

METHODS

The authors identified 563 patients with intracranial HPC in the published literature, 277 of whom had information on the duration of follow-up. Statistical analysis of survival was performed using Kaplan-Meier and Cox regression analysis.

RESULTS

Hemangiopericytoma was diagnosed in 246 males and 204 females, ranging in age from 1 month to 80 years. Among patients treated for HPC, overall median survival was 13 years, with 1-, 5-, 10-, and 20-year survival rates of 95%, 82%, 60%, and 23%, respectively. Gross-total resection alone (105 patients) was associated with superior survival rates overall, with a median survival of 13 years, whereas subtotal resection alone (23 patients) resulted in a median survival of 9.75 years. Subtotal resection plus adjuvant radiotherapy led to a median survival of 6 years. Gross-total resection was associated with a superior survival benefit to patients regardless of the addition or absence of radiation, and patients receiving > 50 Gy of radiation had worse survival outcomes (median survival 4 vs 18.6 years, p < 0.01, log-rank test). Patients with tumors of the posterior fossa had a median survival of 10.75 versus 15.6 years for those with non-posterior fossa tumors (p < 0.05, log-rank test).

CONCLUSIONS

Treatment with gross-total resection provides the greatest survival advantage and should be pursued aggressively as an initial therapy. The addition of postoperative adjuvant radiation does not seem to confer a survival benefit.

Radiosurgery for intracranial hemangiopericytomas: outcomes after initial and repeat Gamma Knife surgery

OBJECT

Intracranial hemangiopericytoma is a rare CNS tumor that exhibits a high incidence of local recurrence and distant metastasis. The purpose of this study was to evaluate the role of Gamma Knife surgery (GKS) in the management of intracranial hemangiopericytomas.

METHODS

In a review of the University of Virginia radiosurgery database between 1989 and 2008, the authors found recurrent or residual hemangiopericytomas after resection in 21 patients in whom radiosurgery was performed to treat 28 discrete tumors. The median age of this population was 47 years (range 31-61 years) at the time of the initial GKS. Prior treatments included embolization (6), transcranial resection (39), transsphenoidal resection (2), and fractionated radiotherapy (8). The mean prescription and maximum radiosurgical doses to the tumors were 17.0 and 40.3 Gy, respectively. Repeat radiosurgery was used to treat 13 tumors. The median follow-up period was 68 months (range 2-138 months).

RESULTS

At last follow-up, local tumor control was demonstrated in 47.6% of the patients (10 of 21 patients) with hemangiopericytomas. Of the 28 tumors treated, 8 decreased in size on follow-up imaging (28.6%), 5 remained unchanged (17.9%), and 15 ultimately progressed (53.6%). The progression-free survival rates were 90, 60.3, and 28.7% at 1, 3, and 5 years after initial GKS. The progression-free survival rate improved to 95, 71.5, and 71.5% at 1, 3, and 5 years after multiple GKS treatments. The 5-year survival rate after radiosurgery was 81%. Prior fractionated irradiation or radiosurgical prescription dose did not correlate with tumor control. In 4 (19%) of 21 patients extracranial metastases developed.

CONCLUSIONS

Radiosurgery is a reasonable treatment option for recurrent hemangiopericytomas. Long-term close clinical and imaging follow-up is necessary because of the high probability of local recurrence and distant metastases. Repeat radiosurgery may be used to treat new or recurrent hemangiopericytomas over a long follow-up course.

A case of primary intracranial hemangiopericytoma with hepatic metastases: successful treatment with radiofrequency ablation and transcatheter arterial chemoembolization

Intracranial hemangiopericytoma is an uncommon soft tissue sarcoma. We report a case of a 54-year-old Japanese female with hepatic metastasis from primary intracranial hemangiopericytoma. At age 44 years the patient underwent primary resection of the intracranial tumor, followed by no adjuvant therapy. At age 53 years she underwent resection of bone metastases in her left upper arm and tenth right rib. The following year, three hepatic tumors with high vascularity were detected by ultrasonography, computed tomography scans, and magnetic resonance imaging. An ultrasound-guided liver biopsy specimen confirmed the diagnosis of hepatic metastases from the primary intracranial hemangiopericytoma. A combination therapy of transcatheter arterial chemoembolization and radiofrequency ablation was performed against the hepatic metastasis. After 5 years, there has been no local recurrence in the liver.

Hemangiopericytoma of the cerebellopontine angle: a case report and review of the literature

BACKGROUND

Intracranial hemangiopericytoma represents a rare intracranial tumor that is typically difficult to distinguish from meningioma based on clinical presentation and radiographic findings. These inherently aggressive neoplasms have been observed to occur in numerous intracranial compartments; however, isolated involvement of the CPA is essentially unreported. The authors present a case of a young lady with presumed right acoustic schwannoma, which proved to be HPC on histopathology. The case is described; and a review of the literature pertaining to the diagnosis, optimal management, and follow-up for these lesions is provided.

CASE DESCRIPTION

A 37-year-old Asian woman presented with a 7-month history of right ear and mandible numbness, as well as subjective hearing loss involving the right ear. Magnetic resonance imaging demonstrated the presence of a homogeneously enhancing extraaxial lesion in the right CPA, radiographically suggestive of an acoustic schwannoma. The lesion proved to be an intracranial HPC on histologic sections. Review of the neurosurgical literature yielded only one prior detailed account of HPC confined to the CPA. The patient underwent right retrosigmoid craniotomy for gross total resection of the mass, followed by stereotactic radiotherapy several weeks postoperatively.

CONCLUSION

Given the fundamentally different treatment approach for HPCs over other more common CPA tumors, it is imperative that the treating surgeon consider this rare diagnosis when evaluating patients with lesions localized to this area. Specifically, gross total resection, followed by adjuvant SRT, provides patients with the highest probability for disease-free survival, based on current evidence in the neurosurgical literature.