Meningeal Solitary Fibrous Tumors with Delayed Extracranial Metastasis

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

Background

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

Materials and Methods

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

Results

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

Conclusions

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

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.

Cerebral Hemangiopericytoma Manifesting as Epilepsia Partialis Continua: A Case Report

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

Keywords

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

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

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

Intracranial Solitary Fibrous Tumor of the Skull Base: 2 Cases and Systematic Review of the Literature

BACKGROUND

Intracranial solitary fibrous tumors (ISFTs) are rare neoplasms of mesenchymal origin that originate from the meninges. ISFTs of the skull base can be challenging to treat, as resection can be complicated by skull base anatomy. We present 2 cases of ISFT, the first manifesting with compressive cranial neuropathy from Meckel cave involvement and the second a posterior fossa lesion causing symptomatic hydrocephalus.

METHODS

A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PubMed database was queried with title/abstract keywords "intracranial," "solitary fibrous tumor," "hemangiopericytoma," "SFT," and "HPC." Search results were reviewed to exclude cases not involving the skull base. References from all selected articles were reviewed for potential additional cases. Patient demographic and clinical data from 58 identified skull base cases were collected for qualitative synthesis.

RESULTS

Visual disturbances were the most common presenting symptom (30 cases, 52%) followed by headache (22 cases, 38%). The most common site of involvement was the sellar/parasellar region (18 cases, 31%) followed by middle fossa/temporal bone (14 cases, 24%). Resection was performed in 55 cases; gross total resection was reported in 26 cases (45%) and subtotal resection was reported in 21 cases (36%). Tumor recurrence was documented in 15 cases (26%) with median and mean follow-up periods of 16 and 29.9 months, respectively.

CONCLUSIONS

We discuss presentation, imaging, histopathology, and management considerations for ISFTs while highlighting the potentially complex nature of skull base lesions and need for multidisciplinary approach to treatment.

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

BACKGROUND

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

CASE DESCRIPTION

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

CONCLUSION

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

A review of solitary fibrous tumor/hemangiopericytoma tumor and a comparison of risk factors for recurrence, metastases, and death among patients with spinal and intracranial tumors

Meningeal solitary fibrous tumors (SFTs) and hemangiopericytomas (HPCs) had been combined into a single classification until 2016. Recurrence and metastases rates are still understudied, especially for spinal SFT/HPCs. Here, we describe CNS SFT/HPCs and predictors for recurrence, metastases, and death, in spinal and intracranial SFT/HPCs, separately. We collected data from studies with patient-level data available on primary SFT/HPCs from multiple online databases. Clinico-demographic data, surgical outcomes, recurrence, metastases, and death rates were abstracted. We used logistic and Cox regression models to identify predictors for recurrence, metastases, and death for spinal and intracranial SFT/HPCs. Twenty-nine studies (368 patients) were included. Higher histological grade and subtotal resection were associated with recurrence (p values < 0.05), while higher histological grade and recurrence (p values < 0.005) were associated with metastases formation. Time to recurrence (p < 0.005) and metastases (p < 0.001) formation were shorter for spinal SFT/HPCs. Death rates were higher among intracranial SFT/HPC patients (p value = 0.001). Among patients with higher histological grade, rates of metastases formation were different between intracranial and spinal SFT/HPCs. Risk of metastases was higher in the first 5 years from surgery for both intracranial and spinal SFT/HPCs. Meningeal SFT/HPCs patients have high rates of recurrence and metastasis, which occur mostly within the first 5 years after diagnosis. Spinal and intracranial SFT/HPCs show similar behavior, but spinal SFT/HPCs tend to develop metastases and recurrences in a shorter interval of time. Careful follow-up for spinal SFT/HPCs should be considered because spinal cases seem to be slightly more aggressive and require more attention.

Case report: neonatal giant forehead hemangiopericytoma with a 5-year follow-up

RATIONALE

Hemangiopericytoma (HPC) is a rare pediatric neoplasm with a high risk of bleeding, aggressive growth and high early relapse rates. Surgical excision remains the mainstream treatment, while the functions of chemotherapy and radiotherapy remain controversial. In particular, an infantile giant extracranial HPC located in the forehead has never been reported.

PATIENT CONCERNS

A 3-day-old girl was delivered normally with a giant tumor localized mainly in the right frontal region. The surface of the mass was filled with vascularity.

DIAGNOSIS

According to the results of imaging and pathological examinations, the diagnosis was HPC grade II.

INTERVENTIONS

Gross total resection of the tumor and the invading partial frontal bone followed by skin scalp reconstruction was carried out without any blood transfusion.

OUTCOMES

No recurrence was identified during 5 years of follow-up. And better outcomes can be achieved without adjuvant therapy.

LESSONS

Multimodality imaging and a collaborative multidisciplinary approach are indispensable for the successful surgical management of infantile HPC, especially for giant tumors and their potential risk of life-threatening bleeding. Gross total resection is the optimal option for infantile HPC, and even without adjuvant therapy, it achieves better outcomes.

Hemangiopericytoma/Solitary Fibrous Tumor in the central nervous system. Experience with surgery and radiotherapy as a complementary treatment: A 10-year analysis of a heterogeneous series in a single tertiary center

Hemangiopericytoma and Solitary Fibrous Tumor are tumors with low incidence. They have a tendency to recur locally and to metastasize. The WHO integrated both tumors into a new entity but one of the pending issues is to demonstrate the effectiveness of surgery plus complementary radiotherapy (RT) and standardize the use of it. We reviewed the data from 10 years. We assessed pathologic and radiologic characteristics. The operation records were evaluated to determine the features and extent of tumor resection. We compared the outcomes in patients using or not RT. The mean follow-up was 74.8 months, with a range of 12 and 210 months. The population included 3 males (30%) and 7 females (70%). The most common location was brain convexity (30%), the remaining were cervical and lumbar spine, sacrum, intraventricular, torcular, sphenoid ridge and intraorbital. Postoperative external beam radiotherapy was delivered in 7 patients (70%), the criteria were a partial resection or WHO II and III histological grades. 2 patients developed local recurrences at 12 and 19 months after initial surgery. 1 patient underwent 2 surgeries, and the other, 4 surgeries. The mean recurrence free survival rate was 15.5 months. Distant metastases were found in 4 patients. 3 of the 10 patients died. Five-year overall survival rate was 66% and mean overall survival was 76 months. A safe and complete resection in the first surgery is the most important prognostic factor. Complementary RT can be helpful, even in cases of complete resection in WHO low-grade.

Solitary fibrous tumor of the pineal region with delayed ectopic intracranial metastasis: A case report and review of the literature

RATIONALE

Solitary fibrous tumors of central nervous system are rare spindle-cell mesenchymal tumors. Although most are benign in nature, malignant transformation and extracranial metastasis have been reported. Up to now, only one case of CSF dissemination was described. Here we described an extremely rare case of intracranial Solitary fibrous tumors arising from the pineal region with a delayed ectopic metastasis.

PATIENT CONCERNS

A 35-year-old female presented with double vision, memory disturbance and unsteady gait was referred to our center. MRI showed an irregular mass in the pineal region.

DIAGNOSES

The patient was diagnosed as pineal tumor, with unknown pathology.

INTERVENTIONS

Gross total resection was achieved and the pathologic studies confirmed a solitary fibrous tumor. Thirty-nine months later local recurrence occurred and gamma-knife radiotherapy was offered. Seven months later, MRI found a metastasis in the left temporal lobe. Surgical resection was conducted and pathological analysis revealed changes in cell morphology, counts and Ki-67 level, confirmed the diagnosis of solitary fibrous tumor/hemangiopericytoma (WHO Grade III). The patient received post-operational radiotherapy.

OUTCOMES

The patient was followed up for 7 months with no signs of recurrence.

LESSONS

Here, we report an extremely rare case of primary solitary fibrous tumor of pineal region with delayed intracranial ectopic metastasis, together with literature review of metastatic solitary fibrous tumors. Strict surveillance is strongly recommended, considering the malignant potential of this seemingly benign disease entity. Complete resection of the tumor is the treatment of first choice and radiotherapy might be an effective adjuvant therapy for high grade SFT/HPCs.

Solitary fibrous tumor/hemangiopericytoma: treatment results based on the 2016 WHO classification

OBJECTIVE

Solitary fibrous tumor/hemangiopericytoma (SFT/HPC) is a new combined entity for which a soft-tissue-type grading system, ranging from grades I to III, has been introduced in the 2016 WHO classification of tumors of the CNS. The results of the treatment of this new disease entity require evaluation.

METHODS

The authors retrospectively reevaluated the pathological findings and medical records of patients with SFT/HPC. This study included 60 patients (27 men and 33 women, median age 42.5 years, range 13-69 years) treated at Severance Hospital between February 1981 and February 2016. Four, 40, and 16 patients were categorized as having SFT/HPC grades I, II, and III, respectively. Among these patients, SFTs diagnosed in 7 patients were regraded as grades I (n = 4), II (n = 2), and III (n = 1).

RESULTS

The median overall survival (OS) was 73.2 months (range 1.4-275.7 months), and the progression-free survival (PFS) after the first operation was 53.8 months (range 1.4-217.7 months). Six patients (10%) showed extracranial metastasis during a median period of 103.7 months (range 31.9-182.3 months). Nineteen patients (31.7%) presented with tumor recurrences. The patients in the grade III group had shorter PFS and OS, as well as a shorter period to extracranial metastasis, compared with patients in the grade II group. In the grade II group, patients who underwent gross-total resection showed longer PFS than those who underwent subtotal resection; however, there was no difference in OS. Patients who underwent adjuvant radiation therapy (RT) after surgery had longer PFS compared with that of patients who did not undergo adjuvant RT.

CONCLUSIONS

The SFT/HPC grade I group showed a relatively benign course compared with those of the other groups. The grade III group presented a course with a more aggressive nature than that of the grade II group. In the grade II group, the extent of resection and adjuvant RT was significantly associated with longer PFS. The long-term follow-up and periodic systemic evaluation are mandatory to detect systemic metastasis.

The Role of Adjuvant Radiation in the Management of Solitary Fibrous Tumors of the Central Nervous System: A National Cancer Database Analysis of 155 Patients

Solitary fibrous tumors (SFT) are a rare neoplasm of mesenchymal origin. There is limited evidence on the epidemiology, treatment, and outcomes of SFT in the central nervous system (CNS). The National Cancer Database (NCDB) was queried for patients diagnosed with an SFT in the CNS as their only tumor diagnosis between 2003 and 2011. The final cohort included 155 patients who received surgery and had adequate information for analysis. Descriptive statistics, logistic regression, and Kaplan-Meier survival analyses were performed. Significance was calculated using a t-test, Fisher’s exact test, chi-square, log-rank test, or Cox model. Twenty-three patients (15%) underwent both surgery and adjuvant radiation while 132 (85%) underwent surgery alone. The treatment groups had comparable demographics and tumor size; median age 53 (range 25-80) and 11 females (48%) in the surgery and adjuvant radiation group, compared to 55 (20-89) and 71 (54%) in the surgery alone group, respectively. Radiotherapy methods included conventional and stereotactic dose and fractionations schemes. Information on margin status and re-resection rates was not available. No variables were significantly associated with receipt of adjuvant radiation. In single (p = 0.78) and multivariable (p = 0.86) survival analyses, the addition of adjuvant radiation did not significantly affect overall survival. Five-year overall survival was 88% with surgery alone versus 93% with adjuvant radiation. SFTs are rare neoplasms, especially in the CNS. Our study did not demonstrate an overall survival benefit for adjuvant radiation. The role of adjuvant radiation is still unclear and warrants further investigation.

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.

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.

Liquid Biopsy in Rare Cancers: Lessons from Hemangiopericytoma

Hemangiopericytoma (HPT) is a rare mesenchymal tumor of fibroblastic type and for its rarity is poorly studied. The most common sites of metastatic disease in patients with intracranial HPT are the bone, liver, and lung, suggestive for an hematogenous dissemination; for this reason, we investigated, for the first time, the presence of circulating tumor cells (CTCs) in hemangiopericytoma patient by CellSearch® and SceenCell® devices. Peripheral blood samples were drawn and processed by CellSearch, an EpCAM-dependent device, and ScreenCell®, a device size based. We found nontypical CTCs by CellSearch system and the immunofluorescence analysis performed on CTCs isolate by ScreenCell demonstrated the presence of single CTCs and CTC clusters. The molecular characterization of single CTCs and CTC clusters, using antibodies directed against EpCAM, CD34, cytokeratins (8, 18, and 19), and CD45, showed a great heterogeneity in CTC clusters. We believe that the present study may open a new scenario in the rare tumors: the introduction of the liquid biopsy and the molecular characterization of circulating tumor cells could lead to personalized targeted treatments and also for rare tumors.

Molecular Testing of Brain Tumor

The World Health Organization (WHO) classification of central nervous system (CNS) tumors was revised in 2016 with a basis on the integrated diagnosis of molecular genetics. We herein provide the guidelines for using molecular genetic tests in routine pathological practice for an accurate diagnosis and appropriate management. While astrocytomas and IDH-mutant (secondary) glioblastomas are characterized by the mutational status of IDH, TP53, and ATRX, oligodendrogliomas have a 1p/19q codeletion and mutations in IDH, CIC, FUBP1, and the promoter region of telomerase reverse transcriptase (TERTp). IDH-wildtype (primary) glioblastomas typically lack mutations in IDH, but are characterized by copy number variations of EGFR, PTEN, CDKN2A/B, PDGFRA, and NF1 as well as mutations of TERTp. High-grade pediatric gliomas differ from those of adult gliomas, consisting of mutations in H3F3A, ATRX, and DAXX, but not in IDH genes. In contrast, well-circumscribed low-grade neuroepithelial tumors in children, such as pilocytic astrocytoma, pleomorphic xanthoastrocytoma, and ganglioglioma, often have mutations or activating rearrangements in the BRAF, FGFR1, and MYB genes. Other CNS tumors, such as ependymomas, neuronal and glioneuronal tumors, embryonal tumors, meningothelial, and other mesenchymal tumors have important genetic alterations, many of which are diagnostic, prognostic, and predictive markers and therapeutic targets. Therefore, the neuropathological evaluation of brain tumors is increasingly dependent on molecular genetic tests for proper classification, prediction of biological behavior and patient management. Identifying these gene abnormalities requires cost-effective and high-throughput testing, such as next-generation sequencing. Overall, this paper reviews the global guidelines and diagnostic algorithms for molecular genetic testing of brain tumors.

Intracranial Solitary Fibrous Tumor

Solitary fibrous tumours are rare mesenchymal spindle-cell tumours that occur most often in the visceral pleura or liver. If they occur intracranially, they are extra-axially located and develop from the meninges. In those cases, the differential diagnosis has to be made with other intracranial extra-axial-located tumours, such as meningeoma and hemangiopericytoma. We report a 32-year-old woman with an intracranial solitary fibrous tumour and review the latest literature regarding the imaging characteristics of this tumour.

Solitary fibrous tumour presenting with a single bone metastasis: report of six cases and literature review

Background

Solitary fibrous tumour (SFT) is a rare soft tissue sarcoma with a low metastatic potential. A higher metastatic rate is observed in the high-grade/dedifferentiated variant. The most common expected site of distant spread are the lungs and the liver. Bone involvement is generally viewed as a late stage of disease spread. We report on a retrospective series of SFT patients relapsing with a single distant bone recurrence as first metastatic event, without evidence of other organ involvement.

Case presentation

All patients affected by a single distant bone metastasis from SFT as first distant event, without any evidence of other site of metastasis, observed at our Institution, were considered. Bone involvement from SFT was pathologically assessed in all cases and confirmed by expert pathologists. A total of six patients were retrospectively identified. Primary tumour arose from the meninges in four patients, from soft tissues in two. Bone metastases were located to the vertebrae, the hip, the acetabulum and the rib. In all cases, bone relapse was the first event, with one patient presenting a local relapse. Median time from the primary tumour and the evidence of bone relapse was 40 months (range 0–58). In 2/6 patients bone metastasis was treated with radiotherapy (RT), in 2/6 with surgery, in 2/6 with surgery plus RT. At a median follow-up of 55 months (range 23–88), 5/6 patients are alive (2/5 without disease, 3/5 with multicentric metastatic disease) and one is dead of disease. 2/6 patients did not relapse after the treatment of the bone metastasis.

Conclusions

This small series in a relatively rare histology suggests that isolated, possibly late, bone metastases are a plausible scenario, in particular in meningeal SFT. Notably, new bone lesions in a patient with a history of SFT should be always investigated. Exclusive local treatments may be an option, though collection of such series would be needed to define the best treatment strategy.

Meningeal Hemangiopericytoma in 33-Year-Old Female; a Case Report

Intracranial hemangiopericytomas (HPC) are rare vascular tumors. They account for 0.4% of primary central nervous system tumors. HPC is more commonly located supratentorially and tends to occur in a younger age group, with average age at presentation of 38-42 years. The tumor was found throughout the entire CNS, usually superficially and closely related to the meninges. Moreover, they have a strong tendency for local recurrence and extracranial metastasis. Given the clinical, pathological and imaging similarities between Hemangiopericytoma and angioblastic/anaplastic meningioma and the necessity of differentiating these two (choosing the proper treatment and prognosis), we present a report of meningeal Hemangiopericytoma tumor in a 33-year-old female. Our study suggests that in addition to routine histopathological examination, immunohistochemical study is essential to differentiate it from other differential diagnosis.