Solitary-fibrous tumor/hemangiopericytoma of the central nervous system: a population-based study

Evaluation of preoperative magnetic resonance imaging features and diagnostic effectiveness of grades II and III intracranial solitary fibroma

OBJECTIVES

To explore the value of preoperative magnetic resonance imaging (MRI) characterization of intracranial solitary fibrous tumors (ISFT) and to evaluate the effectiveness of preoperative MRI features in predicting pathological grading.

MATERIALS AND METHODS

This retrospective analysis comprised the clinical and preoperative MRI characterization of 55 patients with ISFT in our hospital, including 27 grade II cases and 28 grade III cases confirmed by postoperative pathology. Variables included age, sex, tumor location, cross-midline status, signal characteristics of T1-weighted imaging (T1WI), T2-weighted imaging (T2WI), T2-fluid-attenuated inversion recovery (T2-FLAIR), and diffusion‑weighted imaging (DWI), peritumoral edema, intralesional hemorrhage, focal necrosis/cystic degeneration, tumor empty vessel, maximum tumor diameter, maximum, minimum, and average values of apparent diffusion coefficient (ADCmax, ADCmin, and ADCmean), tumors enhancement mode, meningeal tail sign, skull invasion, cerebral parenchymal invasion, and venous sinus involvement. The independent samples t test or Mann-Whitney U test was performed to compare continuous data between the two groups, and the Pearson chi-squared test or Fisher's exact test was used to compare categorical data. In addition, bivariate logistic regression was performed to construct a comprehensive model, and receiver operating characteristic (ROC) curves were generated to calculate the areas under the curve (AUCs), thereby determining the value of each parameter in the differential diagnosis of grades II and III ISFT.

RESULTS

The mean age at onset was similar between patients with grades II and III ISFT (46.77 ± 14.66 years and 45.82 ± 12.07 years, respectively). The proportions of men among patients with grades II and III ISFT were slightly higher than those of female patients (male/female: 1.25 [15/12] and 1.33 [16/12], respectively). There were significant differences between grades II and III ISFT in the T2-FLAIR and DWI signal characteristics, maximum, minimum, and average values of the apparent diffusion coefficient (ADCmax, ADCmin, and ADCmean), tumor location, and skull invasion (P = 0.001, P = 0.018, P = 0.000, P = 0.000, P = 0.000, P = 0.010, and P = 0.032, respectively). However, no significant differences were noted between grades II and III ISFT in age, sex, cross-midline status, T1WI and T2WI signal characteristics, peritumoral edema, intralesional hemorrhage, focal necrosis/cystic degeneration, tumor empty vessel shadow, enhancement mode, meningeal tail sign, maximum tumor diameter, brain parenchyma invasion, or venous sinus involvement (all P > 0.05). Moreover, binary logistic regression analysis showed that the model accuracy was 89.1% when ADCmin was included in the regression equation. Moreover, ROC curve analysis showed that the AUC of ADCmin was 0.805 (0.688, 0.922), sensitivity was 74.1%, specificity was 75.0%, and the cutoff value was 672 mm2/s.

CONCLUSIONS

Grade III ISFT patients displayed more mixed T2-FLAIR signal characteristics and DWI signal characteristics than grade II patients, as shown by higher skull invasion and tumor mass collapse midline distribution and lower ADCmax, ADCmean, and ADCmin values. The ADCmin value was significant in the preoperative assignment of grades II and III ISFT, thereby contributing to enhanced accuracy in the imaging grading diagnosis of the disease.

Intracranial solitary fibrous tumors: Clinical, radiological, and histopathological insights along with review of literature

BACKGROUND

Intracranial solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms, often challenging to diagnose due to their resemblance to meningiomas and other central nervous system tumors. While advancements in molecular genetics have aided in classification, diagnostic nuances and optimal management strategies remain areas of interest.

MATERIALS AND METHODS

This retrospective study analyzed 11 cases of intracranial SFTs treated at a neurosurgical centre in India between February 2020 and January 2024. Clinical data, radiological findings, histopathological features, and follow-up details were reviewed. Immunohistochemistry, particularly STAT6, facilitated diagnosis confirmation.

RESULTS

The median age of presentation was 32 years, with a male predominance. Headache was the most common presenting symptom, often leading to misdiagnosis as meningiomas on radiological imaging. Histologically, SFTs exhibited spindle to ovoid cells with staghorn vessels and collagenized stroma, posing challenges in differential diagnosis. WHO grading predominantly revealed grade 1 tumors, though recurrence occurred, emphasizing the importance of long-term follow-up. Immunohistochemistry, particularly STAT6, played a pivotal role in distinguishing SFTs from other entities.

CONCLUSION

Intracranial SFTs present diagnostic challenges due to overlapping features with other tumors, warranting a comprehensive approach integrating clinical, radiological, and histopathological findings. Immunohistochemistry, particularly STAT6, emerges as a valuable diagnostic tool. Long-term follow-up is essential for monitoring recurrence and potential malignant transformation. Further research is needed to delineate optimal treatment strategies, including the role of radiotherapy in SFT management.

Intracranial Solitary Fibrous Tumor: A Case of a 21-Year-Old Male With Olfactory Hallucination

Meningeal solitary fibrous tumors (SFTs) are a rare central nervous system neoplastic process, resulting in frequent misdiagnosis as meningioma prior to pathologic analysis. Appropriate diagnosis is essential to lowering morbidity and mortality, as Grade II or III SFTs are aggressive neoplasms that possess metastatic potential. The existing data may suggest that intracranial SFTs primarily afflict those in their fourth through sixth decades of life. However, we present the case of a patient outside this demographic presenting with symptoms that we were unable to identify in any prior reports. A 21-year-old male in the United States Navy presented to the emergency department (ED) with a two-month history of progressive headaches, leading to nausea and emesis. The patient also endorsed a daily incidence of the same olfactory hallucination followed by several minutes of palpitations, flushing, and dizziness. His neurologic exam was unremarkable, but imaging in the ED revealed a large mass abutting the right medial sphenoid wing. The radiographic appearance of the mass with a dural tail led to a preoperative diagnosis of meningioma. However, pathologic analysis following gross total resection identified the mass as an SFT. A brief literature review complementary to this case underscored the high variability of intracranial SFT case presentations with a relative scarcity of epidemiologic data due to rarity. This review identified that it was common to initially diagnose SFTs as meningioma, similar to this particular case. This emphasizes the importance of an appropriate pathologic diagnosis. This case adds to the existing literature as anecdotal evidence of SFT occurring in a young patient and a unique symptom profile most notable for olfactory hallucination and dysautonomia as features of focal seizure.

Solitary fibrous tumor occurring at unusual sites: A clinico-pathological series of 31 cases with emphasis on its wide morphological spectrum

Solitary fibrous tumor (SFT) is a relatively rare mesenchymal fibroblastic tumor occurring most commonly in adults with no gender predilection. Although the pathological diagnosis of SFT is usually straightforward, some difficulties may occasionally arise mainly due to the wide morphological spectrum exhibited by this tumor. In the present paper we aimed to evaluate the unusual clinicopathological features in a series of 31 SFTs arising from parenchymal organs, superficial soft tissues and deep soft tissues. Our results emphasize that SFTs may occur anywhere, including unusual sites such as periosteum of the thoracic spine, mesorectal tissue, hepatic hilum, paravescial space, kidney and breast. Moreover, a wide morphological spectrum was observed in tumors included in our series. The most striking morphological features observed included: extensive lipomatous component, myxoid stromal changes, epithelioid cell component, metaplastic mature bone, neurofibroma-like, myxofibrosarcoma-like and pseudoalveolar-like areas. Additionally, multinucleated giant cells and sarcomatous dedifferentiation were also identified. Our paper emphasizes that SFT may occur in unusual anatomical locations and exhibits a wide morphological spectrum. Pathologists must be aware of these features to avoid confusion with other benign and malignant neoplasms that may show overlapping morphological features.

Conditional survival analysis and dynamic survival prediction for intracranial solitary-fibrous tumor/hemangiopericytoma

BACKGROUND

As the form of World Health Organization Central Nervous System (WHO CNS) tumor classifications is updated, there is a lack of research on outcomes for intracranial combined solitary-fibrous tumor and hemangiopericytoma (SFT/HPC). This study aimed to explore conditional survival (CS) pattern and develop a survival prediction tool for intracranial SFT/HPC patients.

METHODS

Data of intracranial SFT/HPC patients was gathered from the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute. The patients were split into training and validation groups at a 7:3 ratio for our analysis. CS is defined as the likelihood of surviving for a specified period of time (y years), given that the patient has survived x years after initial diagnosis. Then, we used this definition of CS to analyze the intracranial SFT/HPC patients. The least absolute shrinkage and selection operator (LASSO) regression and best subset regression (BSR) were employed to identify predictive factors. The Multivariate Cox regression analysis was applied to establish a novel CS-based nomogram, and a risk stratification system was developed using this model.

RESULTS

From the SEER database, 401 patients who were diagnosed with intracranial SFT/HPC between 2000 and 2019 were identified. Among them, 280 were included in the training group and 121 were included in the internal validation group for analysis. Our study revealed that in intracranial SFT/HPC, 5-year survival rates saw significant improvement ranging from 78% at initial diagnosis to rates of 83%, 87%, 90%, and 95% with each successive year after surviving for 1-4 years. The LASSO regression and BSR identified patient age, tumor behavior, surgery and radiotherapy as predictors of CS-based nomogram development. A risk stratification system was also successfully constructed to facilitate the identification of high-risk patients.

CONCLUSION

The CS pattern of intracranial SFT/HPC patients was outlined, revealing a notable improvement in 5-year survival rates after an added period of survival. Our newly-established CS-based nomogram and risk stratification system can provide a real-time dynamic survival estimation and facilitate the identification of high-risk patients, allowing clinicians to better guide treatment decision for these patients.

The role of tumor parenchyma and brain cortex signal intensity ratio in differentiating solitary fibrous tumors and meningiomas

BACKGROUND

Solitary fibrous tumors (SFT) and meningiomas (MA) have similar clinical and radiographic presentations but require different treatment approaches and have different prognoses. This emphasizes the importance of a correct preoperative diagnosis of SFT versus MA.

OBJECTIVE

In this study, investigated the differences in imaging characteristics between SFT and MA to improve the accuracy of preoperative imaging diagnosis of SFT.

METHODS

The clinical and imaging data of 26 patients with SFT and 104 patients with MA who were pathologically diagnosed between August 2017 and December 2022, were retrospectively analyzed. The clinical and imaging differences between SFT and MA, as well as between the various pathological grades of SFT, were analyzed.

RESULTS

Age, gender, cystic change, flow void phenomenon, yin-yang sign, lobulation, narrow base, tumor/cortex signal ratio (TCSR) > 1.0 in T1-weighted imaging (T1WI), TCSR ≥ 1.1 in T2-weighted imaging (T2WI), peritumoral edema, and absence of dural tail sign varied between SFT and MA. As per the receiver operating characteristic (ROC) curve analysis, TCSR > 1 in T1WI has the maximum diagnostic accuracy for SFT. Cranial or venous sinus invasion had a positive effect on SFT (Grade III, World Health Organization (WHO) grading).

CONCLUSION

Among the many radiological and clinical distinctions between SFT and MA, TCSR ≥ 1 exhibits the highest predictive efficacy for SFT; while cranial or venous sinus invasion may be a predictor of WHO grade III SFT.

Surgical Management of Craniospinal Axis Solitary Fibrous Tumors: A Single-Institution Case Series and Comprehensive Review of the Literature

BACKGROUND AND OBJECTIVES

Meningeal solitary fibrous tumors (SFTs) comprise 0.4% of primary central nervous system neoplasms and carry metastatic potential. Disease course and optimal management are largely unknown, and there is currently no literature rigorously describing neurological outcomes in surgically managed SFTs. We present one of the largest craniospinal SFT series, analyze patient outcomes, and extensively review the associated literature.

METHODS

All surgically managed SFTs at our institution between January 2005 and March 2023 were retrospectively reviewed. Patient demographics, tumor and radiographic features, treatment, and clinical outcomes were collected. Neurological function was quantified using Frankel grade and Neurologic Assessment in Neuro-Oncology scores. Descriptive statistics, multivariate analysis, log-rank test, and Kaplan-Meier survival analysis were performed.

RESULTS

Twenty-one patients satisfied inclusion criteria. Tumor locations included 15 supratentorial, three infratentorial, and three spinal. All patients underwent surgical resection, and 16 (76.2%) underwent radiation. Six (28.6%) patients had tumor recurrence, and three (14.3%) developed metastasis. Younger age and higher postoperative Frankel grade were significantly associated with increased overall survival (OS) ( P = .011, P = .002, respectively). All patients symptomatically improved or stabilized after surgery, and Neurologic Assessment in Neuro-Oncology score ( P = .001) and functional status significantly improved postoperatively (Karnofsky Performance Status: 65.2 ± 25.2 vs 91.4 ± 13.5, P = .001). Sex, adjuvant radiation, and extent of resection were not significantly associated with OS.

CONCLUSION

SFT of the central nervous system is a rare entity with a variable clinical course. Surgical resection was associated with improved postoperative functional and neurological status. Higher postoperative neurological function was significantly associated with OS. Further studies are warranted to validate a standardized treatment algorithm and investigate the efficacy of adjuvant radiation in SFT.

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.

MGMT promoter methylation in 1p19q-intact gliomas

OBJECTIVE

Standard-of-care for 1p19q-intact anaplastic gliomas is defined by the international randomized phase III CATNON trial, which found an overall survival (OS) benefit for adjuvant temozolomide (TMZ) when added to radiotherapy. Paradoxically, TMZ did not appear to benefit patients with IDH-wildtype gliomas, regardless of MGMT promoter status. The authors concluded that well-powered prospective study on the clinical efficacy of TMZ for patients with IDH-wildtype anaplastic gliomas (meeting criteria for glioblastoma) is warranted. Given that the prognostic and predictive role of MGMT status for grade 2-3 gliomas is unresolved, we determined the effect of MGMT status on OS in patients with 1p19q-intact gliomas in the National Cancer Database (NCDB).

METHODS

We queried the NCDB from 2018 to 2019 for patients with diffuse (grade 2) and anaplastic (grade 3) IDH-wildtype or -mutant astrocytomas who received chemotherapy with follow-up through 2022. The Kaplan-Meier method and Cox proportional hazards regressions models were used to determine the association of MGMT with OS.

RESULTS

We identified 1514 patients who were newly diagnosed with IDH-wildtype (n = 802, 33% methylated) or -mutant astrocytomas (n = 712, 48% methylated) and received chemotherapy during initial management. An unmethylated promoter was associated with poorer survival in patients with IDH-wildtype (3-year OS 34% [95%CI 29-39%] vs. 46% [95%CI 39-54%], p < .001, adjusted HR 1.53 [95%CI 1.24-1.89]) but not IDH-mutant astrocytomas (3-year OS 79% [95%CI 74-84%] vs. 80% [95%CI 75-86%], p =0 .81, HR 1.04 [95%CI 0.73-1.50]).

CONCLUSIONS

This ancillary analysis supports conclusions from the CATNON trial for adjuvant TMZ as standard-of-care for anaplastic astrocytomas (IDH-mutant and 1p19q-intact), irrespective of MGMT status. Determining the optimal strategy for diffuse gliomas that are IDH-wildtype will be particularly important. MGMT promoter methylation should be considered as a stratification factor in future clinical trials for these patients.

Influenza activity and regional mortality for non-small cell lung cancer

Lung cancer is the leading cause of cancer deaths in the United States and worldwide. While influenza illness is known to be particularly dangerous for frail and elderly patients, the relationship between influenza illness and outcomes in patients with cancer remains largely unknown. The Surveillance, Epidemiology, and End Results (SEER) database was queried to identify patients with non-small cell lung cancer (NSCLC) diagnosed between 2009 and 2015. Influenza-like illness (ILI) activity, provided by the Outpatient Influenza-like Illness Surveillance Network of the Center of Disease for Control and Prevention, was merged with the SEER dataset on the state-month level. Regional monthly mortality rates were compared during low versus high flu months in this ecological cohort study. 202,485 patients with NSCLC from 13 SEER-reporting states were included in the analysis. 53 of 1049 state-months (5.1%) had high flu activity. Monthly mortality rates during low and high flu months were 0.041 (95% CI 0.041-0.042) and 0.051 (95% CI 0.050-0.053), respectively (RR 1.24 [95% CI 1.21-1.27]). The association between ILI activity and mortality was observed at the individual state level and in all clinical and regional subgroups. Increased regional influenza activity is associated with higher mortality rates for patients with NSCLC. Vaccine-directed initiatives and increased awareness amongst providers will be necessary to address the growing but potentially preventable burden of influenza-related lung cancer deaths in the U.S.

Postoperative stereotactic radiosurgery for intracranial solitary fibrous tumors: systematic review and pooled quantitative analysis

BACKGROUND

Intracranial solitary fibrous tumors (SFTs), formerly hemangiopericytomas (HPCs), are rare, aggressive dural-based mesenchymal tumors. While adjuvant radiation therapy has been suggested to improve local tumor control (LTC), especially after subtotal resection, the role of postoperative stereotactic radiosurgery (SRS) and the optimal SRS dosing strategy remain poorly defined.

METHODS

PubMed, EMBASE, and Web of Science were systematically searched according to PRISMA guidelines for studies describing postoperative SRS for intracranial SFTs. The search strategy was defined in the authors' PROSPERO protocol (CRD42023454258).

RESULTS

15 studies were included describing 293 patients harboring 476 intracranial residual or recurrent SFTs treated with postoperative SRS. At a mean follow-up of 21-77 months, LTC rate after SRS was 46.4-93% with a mean margin SRS dose of 13.5-21.7 Gy, mean maximum dose of 27-39.6 Gy, and mean isodose at the 42.5-77% line. In pooled analysis of individual tumor outcomes, 18.7% of SFTs demonstrated a complete SRS response, 31.7% had a partial response, 18.9% remained stable (overall LTC rate of 69.3%), and 30.7% progressed. When studies were stratified by margin dose, a mean margin dose > 15 Gy showed an improvement in LTC rate (74.7% versus 65.7%).

CONCLUSIONS

SRS is a safe and effective treatment for intracranial SFTs. In the setting of measurable disease, our pooled data suggests a potential dose response of improving LTC with increasing SRS margin dose. Our improved understanding of the aggressive biology of SFTs and the tolerated adjuvant SRS parameters supports potentially earlier use of SRS in the postoperative treatment paradigm for intracranial SFTs.

MGMT Promoter Methylation Predicts Overall Survival after Chemotherapy for 1p/19q-Codeleted Gliomas

PURPOSE

While MGMT promoter methylation (mMGMT) is predictive of response to alkylating chemotherapy and guides treatment decisions in glioblastoma, its role in grade 2 and 3 glioma remains unclear. Recent data suggest that mMGMT is prognostic of progression-free survival in 1p/19q-codeleted oligodendrogliomas, but an effect on overall survival (OS) has not been demonstrated.

EXPERIMENTAL DESIGN

We identified patients with newly diagnosed 1p/19q-codeleted gliomas and known MGMT promoter status in the National Cancer Database from 2010 to 2019. Multivariable Cox proportional hazards regression modeling was used to assess the effect of mMGMT on OS after adjusting for age, sex, race, comorbidity, grade, extent of resection, chemotherapy, and radiotherapy.

RESULTS

We identified 1,297 eligible patients, 938 (72.3%) of whom received chemotherapy in their initial course of treatment. The MGMT promoter was methylated in 1,009 (77.8%) patients. Unmethylated MGMT (uMGMT) was associated with worse survival compared with mMGMT [70% {95% confidence interval (CI), 64%-77%} vs. 81% (95% CI, 78%-85%); P < 0.001; adjusted HR (aHR), 2.35 (95% CI, 1.77-3.14)]. uMGMT was associated with worse survival in patients who received chemotherapy [63% (95% CI, 55-73%) vs. 80% (95% CI, 76%-84%); P < 0.001; aHR, 2.61 (95% CI, 1.89-3.60)] but not in patients who did not receive chemotherapy [P = 0.38; HR, 1.31 (95% CI, 0.71-2.42)]. Similar results were observed regardless of World Health Organization grade and after single- or multiagent chemotherapy.

CONCLUSIONS

Our study demonstrates an association between mMGMT and OS in 1p/19q-codeleted gliomas. MGMT promoter status should be considered as a stratification factor in future clinical trials of 1p/19q-codeleted gliomas that use OS as an endpoint.

MGMT promoter methylation in 1p19q-intact gliomas

Objective

Standard-of-care for 1p19q-intact anaplastic gliomas is defined by the international randomized phase III CATNON trial, which found an overall survival (OS) benefit for adjuvant temozolomide (TMZ) when added to radiotherapy. Paradoxically, TMZ did not appear to benefit patients with IDH-wildtype gliomas, regardless of MGMT promoter status. The authors concluded that well-powered prospective study on the clinical efficacy of TMZ for patients with IDH-wildtype anaplastic gliomas (meeting criteria for glioblastoma) is warranted. Given that the prognostic and predictive role of MGMT status for grade 2-3 gliomas is unresolved, we determined the effect of MGMT status on OS in patients with 1p19q-intact gliomas in the National Cancer Database (NCDB).

Methods

We queried the NCDB from 2018-2019 for patients with IDH-wildtype or -mutant astrocytomas who received chemotherapy with follow-up through 2022. The Kaplan-Meier method and Cox proportional hazards regressions models were used to determine the association of MGMT with OS.

Results

We identified 1,514 patients who were newly diagnosed with IDH-wildtype (n = 802, 33% methylated) or - mutant astrocytomas (n = 712, 48% methylated) and received chemotherapy during initial management. An unmethylated promoter was associated with poorer survival in patients with IDH-wildtype (3-year OS 34% [95%CI 29-39%] vs. 46% [95%CI 39-54%], p < .001, adjusted HR 1.53 [95%CI 1.24-1.89]) but not IDH-mutant astrocytomas (3-year OS 79% [95%CI 74-84%] vs. 80% [95%CI 75-86%], p = .81, HR 1.04 [95%CI 0.73-1.50]).

Conclusions

This ancillary analysis supports adjuvant TMZ as standard-of-care for anaplastic astrocytomas (IDH-mutant and 1p19q-intact), irrespective of MGMT status. Determining the optimal strategy for diffuse gliomas that are IDH-wildtype will be particularly important. MGMT promoter methylation should be considered as a stratification factor in future clinical trials for these patients.

Recurrent Solitary Fibrous Tumor in a 73-Year-Old Male Presenting With Small Bowel Obstruction: A Case Report

Solitary fibrous tumors (SFTs) are rare soft tissue tumors that can arise in the abdomen, pleura, and central nervous system, among other sites. Surgical resection is the mainstay of management, although recurrence rates remain substantial. This case describes a 73-year-old male treated surgically for both a recurrent SFT and small bowel obstruction (SBO) secondary to adhesions. The patient had undergone numerous intra-abdominal operations for malignant SFT since 1994, highlighting the importance of meticulous resection at the initial presentation of local disease.

Impact of extent of resection and postoperative radiotherapy on survival outcomes in intracranial solitary fibrous tumors: a systematic review and meta-analysis

The knowledge of optimal treatments for patients with intracranial solitary fibrous tumor (SFT) is limited, with inconclusive results from previous studies. In this study, we conducted a meta-analysis of relevant studies to identify the prognostic impact of the extent of resection (EOR) and postoperative radiotherapy (PORT) on survival outcomes of patients with intracranial SFT. We searched the Medline, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) to identify relevant studies published till April 2022. Progression-free survival (PFS) and overall survival (OS) were the outcomes of interest. Differences between two cohorts (gross total resection [GTR] vs. subtotal resection [STR] and PORT vs. surgery only) were estimated by calculating hazard ratios. Twenty-seven studies were selected for the meta-analysis, including data of 1348 patients (GTR, n = 819 vs. STR, n = 381 and PORT, n = 723 vs. surgery only, n = 578). Pooled hazard ratios of PFS (1, 3, 5, and 10 years) and OS (3, 5, and 10 years) revealed that the GTR cohort showed sustained superiority over the STR cohort. In addition, the PORT cohort was superior to the surgery-only cohort with respect to all PFS periods. Although the 10-year OS between the two cohorts was not statistically different, PORT showed significantly better 3- and 5-year OS than surgery only. The study findings suggest that GTR and PORT provide significant benefits for PFS and OS. Aggressive surgical resection of tumors to achieve GTR followed by PORT should be implemented as optimal treatments for all patients with intracranial SFT when feasible.

The Role of Immunotherapy in the Treatment of Rare Central Nervous System Tumors

Establishing novel therapies for rare central nervous system (CNS) tumors is arduous due to challenges in conducting clinical trials in rare tumors. Immunotherapy treatment has been a rapidly developing field and has demonstrated improvements in outcomes for multiple types of solid malignancies. In rare CNS tumors, the role of immunotherapy is being explored. In this article, we review the preclinical and clinical data of various immunotherapy modalities in select rare CNS tumors, including atypical meningioma, aggressive pituitary adenoma, pituitary carcinoma, ependymoma, embryonal tumor, atypical teratoid/rhabdoid tumor, and meningeal solitary fibrous tumor. Among these tumor types, some studies have shown promise; however, ongoing clinical trials will be critical for defining and optimizing the role of immunotherapy for these patients.

The value of whole-volume apparent diffusion coefficient histogram analysis in preoperatively distinguishing intracranial solitary fibrous tumor and transitional meningioma

Purpose

To investigate the value of whole-volume apparent diffusion coefficient (ADC) histogram analysis in preoperatively distinguishing intracranial solitary fibrous tumors (SFT) from transitional meningiomas (TM), thereby assisting the establishment of the treatment protocol.

Methods

Preoperative diffusion-weighted imaging datasets of 24 patients with SFT and 28 patients with TM were used to extract whole-volume ADC histogram parameters, including variance, skewness, kurtosis, and mean, as well as 1st (AP1), 10th (AP10), 50th (AP50), 90th (AP90), and 99th (AP99) percentiles of ADC using MaZda software. The independent t-test or Mann-Whitney U test was used to compare the differences between ADC histogram parameters of SFT and TM. Receiver operating characteristic (ROC) curves were generated to evaluate the performance of significant ADC histogram parameters. Spearman's correlation coefficients were calculated to evaluate correlations between these parameters and the Ki-67 expression levels.

Results

SFT exhibited significantly higher variance, and lower AP1 and AP10 (all P < 0.05) than TM. The best diagnostic performance was obtained by variance, with an area under the ROC curve of 0.848 (0.722-0.933). However, there was no significant difference in skewness, kurtosis, mean, or other percentiles of ADC between the two groups (all P > 0.05). Significant correlations were also observed between the Ki-67 proliferation index and variance (r = 0.519), AP1 (r = -0.425), and AP10 (r = -0.372) (all P < 0.05).

Conclusion

Whole-volume ADC histogram analysis is a feasible tool for non-invasive preoperative discrimination between intracranial SFT and TM, with variance being the most promising prospective parameter.

Risk Stratification for Management of Solitary Fibrous Tumor/Hemangiopericytoma of the Central Nervous System

INTRODUCTION

Solitary fibrous tumor/hemangiopericytoma (SFT/HPC) of the central nervous system (CNS) is a rare meningeal tumor. Given the absence of prospective or randomized data, there are no standard indications for radiotherapy. Recently, the NRG Oncology and EORTC cooperative groups successfully accrued and completed the first prospective trials evaluating risk-adapted adjuvant radiotherapy strategies for meningiomas. Using a similar framework, we sought to develop prognostic risk categories that may predict the survival benefit associated with radiotherapy, using two large national datasets.

METHODS

We queried the National Cancer Database (NCDB) and the Surveillance, Epidemiology, and End Results (SEER) databases for all newly diagnosed cases of SFT/HPC within the CNS. Risk categories were created, as follows: low risk-grade 1, with any extent of resection (EOR) and grade 2, with gross-total resection; intermediate risk-grade 2, with biopsy/subtotal resection; high risk-grade 3 with any EOR. The Kaplan-Meier method and Cox proportional hazards regressions were used to determine the association of risk categories with overall and cause-specific survival. We then determined the association of radiotherapy with overall survival in the NCDB, stratified by risk group.

RESULTS

We identified 866 and 683 patients from the NCDB and SEER databases who were evaluated, respectively. In the NCDB, the 75% survival times for low- (n = 312), intermediate- (n = 239), and high-risk (n = 315) patients were not reached, 86 months (HR 1.60 (95% CI 1.01-2.55)), and 55 months (HR 2.56 (95% CI 1.68-3.89)), respectively. Our risk categories were validated for overall and cause-specific survival in the SEER dataset. Radiotherapy was associated with improved survival in the high- (HR 0.46 (0.29-0.74)) and intermediate-risk groups (HR 0.52 (0.27-0.99)) but not in the low-risk group (HR 1.26 (0.60-2.65)). The association of radiotherapy with overall survival remained significant in the multivariable analysis for the high-risk group (HR 0.55 (0.34-0.89)) but not for the intermediate-risk group (HR 0.74 (0.38-1.47)). Similar results were observed in a time-dependent landmark sensitivity analysis.

CONCLUSION

Risk stratification based on grade and EOR is prognostic of overall and cause-specific survival for SFT/HPCs of the CNS and performs better than any individual clinical factor. These risk categories appear to predict the survival benefit from radiotherapy, which is limited to the high-risk group and, potentially, the intermediate-risk group. These data may serve as the basis for a prospective study evaluating the management of meningeal SFT/HPCs.

Head and Neck Sarcoma Tumor Board Survival Guide for Neuroradiologists: Imaging Findings, History, and Pathology

Sarcomas of the head and neck carry a poor prognosis as diagnosis is often delayed until a late stage of the disease. Accordingly, it is essential to be familiar with the clinical and imaging features of sarcomas to suggest an appropriate differential diagnosis for collaborating surgeons and pathologists. However, as there are only 1000-1500 cases in the United States annually, many radiologists lack experience with pertinent imaging findings of sarcoma and lack knowledge of both treatment and necessary follow-up. In this review, a brief discussion of WHO definitions and histopathology is included to decode information provided by pathologists. Finally, staging and treatments are illuminated to aid the radiologist with initial imaging staging and follow-up care. This review aims to increase the comprehensive knowledge of a neuroradiologist and further their value to the multidisciplinary tumor board.

Endoscopic endonasal resection of two rare cases of hemangiopericytomas invading the cavernous sinus and literature review

Hemangiopericytomas (HPCs) invading the cavernous sinus (CS) are extremely rare invasive tumors that have a great propensity for local recurrence. To date, only eight cases have been reported in the literature. Owing to the abundant vascular supply of HPCs, intracavernous bleeding and important blood vessels and nerves passing through the CS, it is very difficult and challenging for neurosurgeons to completely resect HPCs. Here, we report two cases of HPCs invading the CS and introduce their clinical manifestations, imaging findings, surgical approaches and histopathological features in detail. We have implemented the surgery by the endoscopic transpterygoid transcavernous approach (ETPTCa) for the two patients, and one patient has undergone gross total resection (GTR) and another has undergone subtotal resection (STR) and postoperative stereotactic radiosurgery (SRS). The ETPTCa may serve as a viable option to facilitate HPCs resection. Radiotherapy is helpful in prolonging progression-free survival (PFS) following STR of the tumor.

Effect of Different Treatments for Intracranial Solitary Fibrous Tumors: Retrospective Analysis of 31 Patients

OBJECTIVE

An intracranial solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm with a high predisposition toward recurrence and metastasis. The definition of SFT was updated according to the 2021 World Health Organization (WHO) classification. Given its rarity and resemblance to meningiomas, SFT is often misdiagnosed and there remains a debate on the treatment for it. We provide a retrospective analysis of SFTs and conclude the outcomes of different treatments.

METHODS

Patients who accepted operation and were diagnosed with intracranial SFTs in our hospital were included between 2008 and 2021. The medical records on clinical characteristics and outcomes were summarized for analysis. Cox regressions were used to determine the hazard ratio (HR).

RESULTS

Thirty-one SFT patients were included with a median follow-up time of 67 months. Tumor recurrence was observed in 12 (38.7%) patients, with 1 and 5-year recurrence rates of 6.5% and 22.6%, respectively. In univariate analysis, gross total resection (GTR) was significantly associated with decreased recurrence (P = 0.022), while subtotal resection (STR) (HR = 9.237; P = 0.020) and tumor location of tentorium (HR = 4.692; P = 0.022) were correlated with increased recurrence. In multivariate analysis, GTR (P = 0.040) and GTR plus radiotherapy (GTR + RT) (HR = 0.002; P = 0.020) were associated with reduced recurrence, while STR (HR = 40.835; P = 0.012) was a risk factor for recurrence.

CONCLUSIONS

GTR and postoperative RT are beneficial for preventing tumor recurrence. Larger studies and long-term follow-up are warranted to further identify the effect of postoperative RT.

Toward Better Understanding and Management of Solitary Fibrous Tumor

Solitary fibrous tumor (SFT) comprises a histologic spectrum of soft tissue neoplasms that are characterized by the unique NAB2-STAT6 gene fusion. Changes in diagnostic terminology and site-specific classification over the past few decades have resulted in a disjointed literature. Complete surgical excision with preservation of function remains the mainstay of treatment. New risk stratification systems including risk factors such as mitotic rate, age, tumor size, and presence of necrosis, among others, can be used to predict risk of recurrence or metastasis. Long-term follow-up after surgical resection is recommended. The clinical manifestations, diagnosis, management, and prognosis of SFT are reviewed here.

Solitary Fibrous Tumors of the Head and Neck: A Single-Institution Study of 52 Patients

Objective

To evaluate the clinicopathologic characteristics of head and neck solitary fibrous tumors and features that may predict tumor recurrence.

Study Design

Retrospective review.

Setting

University of California–Los Angeles Medical Center.

Methods

A single-center retrospective study was conducted on pathologically confirmed cases of head and neck solitary fibrous tumors between 1996 and 2021. Patient demographics, clinical course, and histopathologic features were evaluated. Recurrence-free survival was estimated via Kaplan-Meier analysis.

Results

A total of 52 patients were reviewed. The average patient age was 54.7 years (range, 15-89). The most common subsite was the orbit (53.8%, n = 28), but other involved areas included the nasopharynx, paranasal sinuses, and scalp. The median tumor size was 2.95 cm (range, 1.3-11.2). Strong STAT6 (100%) and CD34 (97.9%) expression was observed on immunohistochemistry. Almost all patients were initially managed with wide local excision; 82% of patients (n = 14) had positive margins on pathologic review; and 15% (n = 4) had recurrence at a median 28.5 months (range, 10-113). White patient race was the only significant predictor of tumor recurrence. Patient age (≥55 years), tumor size (≥4), high mitotic rate, and disease subsite were not associated with recurrence.

Conclusion

Head and neck solitary fibrous tumors demonstrate a significantly larger local recurrence rate as compared with their rate of metastasis. They can recur many years following initial therapy, warranting long-term surveillance and follow-up to assess for tumor recurrence.

Clinical Features, Management, and Prognostic Factors of Intracranial Solitary Fibrous Tumor

Background

Because of the low incidence and the constantly changing diagnostic and classification criteria, the clinical features, management, and prognostic factors of intracranial solitary fibrous tumor (ISFT) remain unclear and were thus analyzed in this study.

Method

A total of 38 patients with ISFTs who were diagnosed in our institution were enrolled in this study. Patient data including age, gender, clinical presentation, histopathological features, immunohistochemistry staining, tumor location, tumor size, treatment methods, and prognosis were extracted and retrospectively analyzed.

Results

The median age at diagnosis was 45.5 years (range 28–66 years) and the male-to-female ratio was 1:1.53 in our series. The 3-, 5-, and 10-year progression-free survival (PFS) rate was 82.2%, 62.8%, and 21.4%, respectively; and the 3-, 5-, and 10-year overall survival rate was 97.1%, 86.9%, and 64.2%, respectively. Patients with high WHO grade (grade 3) ISFTs experienced impaired PFS (p < 0.05) and OS (p < 0.01). Subtotal resection (STR) was associated with worse PFS and OS (p < 0.001, respectively). Postoperative radiotherapy (PORT) improved PFS, especially local control rate, in patients with WHO grade 3 ISFTs (P = 0.025) or STR (p = 0.027). Moreover, CD34-negative immunostaining and a high Ki-67 index (>10%) were associated with impaired PFS in ISFTs.

Conclusion

Our study provides evidence that high tumor grade, subtotal tumor resection, CD34 negative immunostaining, and high Ki-67 index (>10%) were independent predictors for the poor prognosis of ISFTs. PORT can improve local control rate, and should be recommended for patients with high-grade ISFTs or STR.

Clinical outcomes in central nervous system solitary-fibrous tumor/hemangiopericytoma: a STROBE-compliant single-center analysis

Background

Solitary fibrous tumor (SFT) and hemangiopericytoma (HPC) are rare mesenchymal tumors in the central nervous system with a high tendency to relapse, having a significant impact on quality of life (QoL). Due to the rarity of intracranial SFT/HPC, the prognostic factors and optimal treatment remain to be elucidated. Meanwhile, quality of life in patients with intracranial SFT/HPC is seldomly concerned. Thus, we aim to survey about the quality of life and underline some aspects demanding concern in intracranial SFT/HPC treatment through summarizing our case series in recent ten years.

Methods

Patients with intracranial SFT/HPC who underwent surgical resection from January 2009 to June 2019 were included in the study. Clinical features, such as age, gender, and resection extent, were collected. The EuroQol Five Dimensions Questionnaire (EQ-5D) was used to assess the patients’ quality of life (QoL). Prognosis factors related to progression-free survival (PFS) and overall survival (OS) were also evaluated.

Results

Thirty-six patients with a mean follow-up period of 61.6 months (range 13–123 months) were included in this study. Sixteen (44.4%) patients achieved gross total resection (GTR). Fourteen patients (38.9%) with tumor progression experienced adjuvant radiotherapy (11.1%) or Gamma Knife surgery (GKS, 27.8%). According to the 2016 WHO classification, there were 6 (16.7%) grade I SFT/HPC, 11 (30.5%) grade II SFT/HPC, and 19 (52.8%) grade III SFT/HPC. The PFS and OS were 29 months (range 4–96 months) and 38 months (range 4–125 months). The median EQ5D-3 L tariff with or without progression was 0.617 (95% CI 0.470–0.756) and 0.939 (95% CI 0.772–0.977) respectively. Gross total resection (GTR, p = 0.024) and grade I SFT/HPC (p = 0.017) were significantly associated with longer PFS. In multivariate analysis, GTR (HR 0.378, 95% CI 0.154–0.927) and adjuvant therapy (HR 0.336, 95% CI 0.118–0.956) result in significantly longer PFS in patients with SFT/HPC.

Conclusions

Patients underwent GTR and adjuvant therapy had longer PFS. Similarly, patients with lower WHO grade had relatively longer PFS. Therefore, GTR is advocated for the treatment of SFT/HPC. And adjuvant therapy such as GKS could be an alternative treatment for patients who underwent STR or with tumor progression. Further, the QoL decreased in patients with tumor progression and metastasis, and more attention is demanded to the QoL of intracranial SFT/HPC patients.

Deep Learning Model for Intracranial Hemangiopericytoma and Meningioma Classification

Background

Intracranial hemangiopericytoma/solitary fibrous tumor (SFT/HPC) is a rare type of neoplasm containing malignancies of infiltration, peritumoral edema, bleeding, or bone destruction. However, SFT/HPC has similar radiological characteristics as meningioma, which had different clinical managements and outcomes. This study aims to discriminate SFT/HPC and meningioma via deep learning approaches based on routine preoperative MRI.

Methods

We enrolled 236 patients with histopathological diagnosis of SFT/HPC (n = 144) and meningioma (n = 122) from 2010 to 2020 in Xiangya Hospital. Radiological features were extracted manually, and a radiological diagnostic model was applied for classification. And a deep learning pretrained model ResNet-50 was adapted to train T1-contrast images for predicting tumor class. Deep learning model attention mechanism was visualized by class activation maps.

Results

Our study reports that SFT/HPC was found to have more invasion to venous sinus (p = 0.001), more cystic components (p < 0.001), and more heterogeneous enhancement patterns (p < 0.001). Deep learning model achieved a high classification accuracy of 0.889 with receiver-operating characteristic curve area under the curve (AUC) of 0.91 in the validation set. Feature maps showed distinct clustering of SFT/HPC and meningioma in the training and test cohorts, respectively. And the attention of the deep learning model mainly focused on the tumor bulks that represented the solid texture features of both tumors for discrimination.

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

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

Novel Therapeutic Options for Solitary Fibrous Tumor: Antiangiogenic Therapy and Beyond

SFT is an ultrarare mesenchymal ubiquitous tumor, with an incidence rate <1 case/million people/year. The fifth WHO classification published in April 2020 subdivided SFT into three categories: benign (locally aggressive), NOS (rarely metastasizing), and malignant. Recurrence can occur in up to 10-40% of localized SFTs, and several risk stratification models have been proposed to predict the individual risk of metastatic relapse. The Demicco model is the most widely used and is based on age at presentation, tumor size, and mitotic count. Total en bloc resection is the standard treatment of patients with a localized SFT; in case of advanced disease, the clinical efficacy of conventional chemotherapy remains poor. In this review, we discuss new insights into the biology and the treatment of patients with SFT. NAB2-STAT6 oncogenic fusion, which is the pathognomonic hallmark of SFT, is supposedly involved in the overexpression of vascular endothelial growth factor (VEGF). These specific biological features encouraged the successful assessment of antiangiogenic drugs. Overall, antiangiogenic therapies showed a significant activity toward SFT in the advanced/metastatic setting. Nevertheless, these promising results warrant additional investigation to be validated, including randomized phase III trials and biological translational analysis, to understand and predict mechanisms of efficacy and resistance. While the therapeutic potential of immunotherapy remains elusive, the use of antiangiogenics as first-line treatment should be considered.

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.

A Large Benign Solitary Fibrous Tumor in the Pelvis: A Unique Group

Solitary fibrous tumors (SFTs) are a rare type of sarcoma and ubiquitous in nature, occurring anywhere in the body. Although only a few hundred cases have been described so far, certain histological features, such as hypercellularity and high mitotic index, have been associated with a more malignant course. Tumor sizes larger than 10 cm have also been associated with higher recurrence rates. There are clinical recommendations for two distinct patient groups, those with small and benign SFTs or those with large and malignant SFTs. There are few that acknowledge the unique group of those with large but benign tumors. A case involving a 62-year-old man who underwent surgical resection of a large but benign solitary fibrous tumor of the pelvis is described.

Skull base hemangiopericytomas

OBJECTIVE

To retrospectively evaluate the clinical outcome of six patients with skull base hemangiopericytomas (HPCs) and that of a cohort of 37 similar patients identified by a systematic review of the literature.

METHODS

The series constitutes of three men and three women with newly diagnosed skull base HPC who underwent multimodal treatment including surgery, external beam radiotherapy (EBRT) and pre-operative embolization. Furthermore, a systematic review off the literature identified 37 reports of primarily intracranial skull base HPCs.

RESULTS

Four patients had a gross total resection (GTR) and two patients had a near total resection. Five patients were referred for adjuvant EBRT with a survival ranging from 15 to 47 months. All patients had an excellent outcome and resumed their previous activities. Literature review identified 37 additional patients with skull base HPC. Altogether, tumors were unevenly distributed above and below tentorium. GTR was achieved in half the patients, and 72.1% were referred to EBRT. Out of 37 reported patients in the literature, survival longer than 1 year was described in only 24. Within the combined cohort including the present series, survival was 83.6 months.

CONCLUSIONS

The present series shows that a radical resection of HPC can be achieved under the difficult anatomical conditions of skull base surgery. Pre-operative arterial embolization may be instrumental to maintain a clear visual field and prevent excessive blood loss. Finally, the results of the present cohort suggest that EBRT may be useful for local growth control, as an effective palliative measure for skull base HPCs.

Intracranial solitary fibrous tumor/hemangiopericytoma: tumor reclassification and assessment of treatment outcome via the 2016 WHO classification

PURPOSE

As per the 2016 World Health Organization (WHO) guidelines on the classification of central nervous system tumors, solitary fibrous tumors (SFTs) and hemangiopericytomas (HPCs) constitute a single disease entity, known as SFT/HPC. This study provides a clinical analysis of these tumors and describes the treatment outcomes of SFT/HPCs.

METHODS

This retrospective study included 76 patients with histopathologically proven SFT/HPC. Reclassification according to the 2016 WHO guideline was done for patients who were diagnosed with SFT or HPC based on the 2007 WHO classification. Recurrence-free survival (RFS) and overall survival (OS) were evaluated for all patients and subgroups.

RESULTS

The median follow-up period was 77.9 months. The median RFS and OS were 126.5 and 136.8 months, respectively. The 1-, 5-, 10-, and 15-year RFS rates were 93%, 72%, 40%, and 40%, respectively. The 1-, 5-, 10- and 15-year OS rates were 97%, 89%, 54%, and 35%, respectively. In multivariable analyses, stereotactic radiosurgery (SRS; p = 0.009, hazard ratio [HR] 6.986), female sex (p = 0.023, HR 1.76), and age over 45 (p = 0.037, HR 2.74) were associated with shorter RFS. Patients who underwent SRS as initial treatment had a shorter OS than that of patients who underwent primary resection (p < 0.001, HR 12.86).

CONCLUSIONS

High-grade tumors tended to have worse OS and occur extracranial metastases earlier than low-grade tumors. The median RFS was not different between grade II and III tumors. Male sex, younger age, and GTR were associated with a better RFS. A history of SRS before tumor resection was associated with a shorter RFS and OS.

Tumor volume and the dural tail sign enable the differentiation of intracranial solitary fibrous tumor/hemangiopericytoma from high-grade meningioma

OBJECTIVES

Intracranial solitary fibrous tumor/hemangiopericytoma (SFT/HPC) is a rare mesenchymal neoplasm with imaging features mimicking high-grade meningioma (HGM) and can easily be misdiagnosed. We sought to determine the value of routine preoperative data in differentiating these tumors.

PATIENTS AND METHODS

Patients with confirmed SFT/HPC or HGM between January 2012 and June 2020 were identified. A total of 28 preoperative variables (including age, sex, tumor location, tumor volume, 10 traditional MRI features, and 14 peripheral blood indices) were collected for each patient. The top features were selected sequentially based on the least absolute shrinkage and selection operator (LASSO) and support vector machines-recursive feature elimination (SVM-RFE) methods. Differentiation and calibration of the classifiers were assessed by receiver operating characteristic (ROC) curves and calibration curves, respectively. Nomograms were constructed based on multivariate analysis.

RESULTS

A total of 127 patients, including 29 with SFT/HPC and 98 with HGM, were analyzed. Three features were first selected using the LASSO and SVM-RFE methods, and corresponding models were developed. Although the area under the curve (AUC) of model 1 was the highest, a comprehensive analysis suggested the superiority of model 2, which consisted only of the features tumor volume (TV) and dural tail sign (DTS) (AUC: 0.942, sensitivity: 93.10%, p-value of H-L test: 0.734, Brier score: 0.07). A risk score formula and a nomogram were constructed.

CONCLUSIONS

TV can be used to effectively identify SFT/HPC and HGM, whereas adding DTS can improve the overall prediction accuracy. As these two variables are routinely available and are easy for clinicians to master, they can provide a powerful reference for clinical decision-making.

A Comprehensive Review on Solitary Fibrous Tumor: New Insights for New Horizons

Simple Summary

Solitary fibrous tumor (SFT) is a malignant condition that exhibits different clinical behaviors ranging from low to high aggressive SFT, with dedifferentiated SFT (DD-SFT) being the fastest-growing subtype. Even when surgery alone provides curation rates above 60%, recurrences do occur in a fraction of patients where surgery is unable to provide disease control. Among the systemic therapeutic options, antiangiogenic compounds have shown higher efficacy than chemotherapy by indirect comparisons. Furthermore, rotating different antiangiogenics, at the progression time, has been shown to be effective. The exception is DD-SFT since it is resistant to antiangiogenics but can respond to chemotherapy. This comprehensive review also analyzes the underlying molecular components that play a key role in SFT origin and aggressiveness. The discovery in 2013 of anomalous fusion genes between NAB2 and STAT6 was determinant to increase the knowledge on the molecular drivers in SFT that could be potential targets for future therapies.

Abstract

Solitary fibrous tumor (SFT) is a rare mesenchymal, ubiquitous tumor, with an incidence of 1 new case/million people/year. In the 2020 WHO classification, risk stratification models were recommended as a better tool to determine prognosis in SFT, to the detriment of “typical” or “malignant” classic terms. The risk for metastasis is up to 35–45%, or even greater, in series with a longer follow-up. Over the last few decades, advances in immunohistochemistry and molecular diagnostics identified STAT6 nuclear protein expression and the NAB2–STAT6 fusion gene as more precise tools for SFT diagnosis. Recent evidence taken from retrospective series and from two prospective phase II clinical trials showed that antiangiogenics are active and their sequential use from first line should be considered, except for dedifferentiated SFT for which chemotherapy is the best option. Since the fusion transcript driver’s first description in 2013, new insights have been brought on key molecular events in SFT. This comprehensive review mainly focuses on the superior efficacy of antiangiogenics over chemotherapeutic agents in SFT, provides the current knowledge of key molecules that could co-drive the SFT behavior, and suggests new target candidates that deserve to be explored in preclinical and clinical research in SFT.

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.

Management of meningeal solitary fibrous tumors/hemangiopericytoma; surgery alone or surgery plus postoperative radiotherapy?

INTRODUCTION

A meningeal solitary fibrous tumor (SFT), also called hemangiopericytoma, is a rare mesenchymal malignancy. Due to anatomic constrains, even after macroscopic complete surgery with curative intent, the local relapse risk is still relatively high, thus increasing the risk of dedifferentiation and metastatic spread. This study aims to better define the role of postoperative radiotherapy (RT) in meningeal SFTs.

PATIENTS AND METHODS

A retrospective study was performed across seven sarcoma centers. Clinical information was retrieved from all adult patients with meningeal primary localized SFT treated between 1990 and 2018 with surgery alone (S) compared to those that also received postoperative RT (S + RT). Differences in treatment characteristics between subgroups were tested using independent samples t-test for continuous variables and chi-square tests for proportions. Local control (LC) and overall survival (OS) rates were calculated as time from start of treatment until progression or death from any cause. LC and OS in groups receiving S or S + RT were compared using Kaplan-Meier survival curves.

RESULTS

Among a total of 48 patients, 7 (15%) underwent S and 41 (85%) underwent S + RT. Median FU was 65 months. LC was significantly associated with treatment. LC after S at 60 months was 60% versus 90% after S + RT (p = 0.052). Furthermore, R1 resection status was significantly associated with worse LC (HR 4.08, p = 0.038). OS was predominantly associated with the mitotic count (HR 3.10, p = 0.011).

CONCLUSION

This retrospective study, investigating postoperative RT in primary localized meningeal SFT patients, suggests that combining RT to surgery in the management of this patient population may reduce the risk for local failures.

Outcomes for localized treatment of large cell neuroendocrine carcinoma of the lung in the United States

Background

Treatment paradigms for large cell neuroendocrine carcinoma (LCNEC) of the lung are based largely upon small retrospective studies and smaller prospective trials. It is unclear if these tumors behave like non-small cell lung cancer (NSCLC) or small cell lung cancer (SCLC). Data are lacking with regard to the role of radiotherapy (RT). U. S. guidelines recommend that LCNEC be treated as a NSCLC. We sought to perform a cross-sectional study of LCNEC cases to understand treatment paradigms and outcomes in this disease.

Methods

The Surveillance, Epidemiology and End Results database was queried for cases of stage I-III pulmonary LCNEC diagnosed 2004-2013. Treatment groups were defined as no surgery, RT alone, surgery alone, and surgery + RT. The Cox-proportional hazards regression model was used to compare overall survival and cause-specific survival (OS/CSS), stratified by AJCC 6th Staging. Factors that were significant on univariable analysis were included in multivariable analysis.

Results

We identified 1,523 cases of LCNEC, with 748, 177, and 598 cases of stage I, II, and III disease, respectively. In stage I and II disease, RT was associated with improved survival for non-surgical patients, but not for those who underwent surgery. In stage I disease, the adjusted hazard ratios for OS for RT alone, surgery, and surgery + RT were 0.39, 0.21, and 0.22, respectively (P<0.001). In stage II disease, the adjusted hazard ratios for RT alone, surgery, and surgery + RT were 0.51 (P=0.15), 0.39 (P=0.004), and 0.38 (P=0.01), respectively. For patients with stage III disease, RT was associated with improved survival in surgical and non-surgical patients. The adjusted hazard ratios for RT alone, surgery, and surgery + RT were 0.49, 0.43, and 0.36, respectively (P<0.001).

Conclusions

Our findings indicate that non-metastatic LCNEC may be treated as a NSCLC with respect to RT. Prospective studies are necessary to increase our understanding of optimal treatment regimens.

Signet ring cell carcinoma of the Ampulla of Vater: outcomes of patients in the United States

BACKGROUND

Signet ring cell carcinoma (SRCC) of the ampulla of Vater is poorly understood, with approximately 22 reported cases. Our study sought to create a comprehensive review of cases in the United States.

METHODS

We used the Surveillance, Epidemiology, and End Results Program to collect all cases of ampullary adenocarcinoma diagnosed between 2010 and 2015.

RESULTS

The age-adjusted incidence rate of SRCC of the ampulla of Vater was 1.2 cases per 10,000,000 persons per year, with 50% more cases in males than females. We identified 3448 cases of adenocarcinoma of the ampulla of Vater, 81 of which were SRCC (2.3%). SRCC tended to present a later stage than other ampullary cancers, with median survival times of 17 vs. 25 months, (p = 0.07). Survival was significantly worse for SRCC when accounting for other clinical features (HR 1.46, p = 0.01). Factors portending worse prognosis in SRCC of the ampulla of Vater were advanced age, late stage and lack of surgical intervention.

CONCLUSION

Our study represents the largest study of SRCC of the ampulla of Vater to date. SRCC has a poorer prognosis compared with other ampullary cancers. Optimal treatment regimen is the most important future area of study.

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.

Grade III Solitary Fibrous Tumor/Hemangiopericytoma: A Rare Case of a World Health Organization Grade III Anaplastic Hemangiopericytoma

Solitary fibrous tumors (SFTs) and hemangiopericytomas (HPCs) have been combined into a single designation in the most recent World Health Organization (WHO) guidelines as solitary fibrous tumor/hemangiopericytoma (SFT/HPC). These rare intracranial tumors can present as WHO grade I, II, or III tumors, with the risk of recurrence, metastasis, and mortality worsening with higher-grade tumors. We present a case of a patient with a WHO grade III SFT/HPC with an emphasis on the imaging features that help differentiate this type of tumor from meningiomas, which are much more common and can appear similar. Being able to help differentiate these tumors by their imaging appearance is important to help triage and risk-stratify patient management decisions.

Extrameningeal solitary fibrous tumors-surgery alone or surgery plus perioperative radiotherapy: A retrospective study from the global solitary fibrous tumor initiative in collaboration with the Sarcoma Patients EuroNet

Background

Solitary fibrous tumor (SFT) is a rare mesenchymal malignancy. Although surgery is potentially curative, the local relapse risk is high after marginal resections. Given the lack of prospective clinical trial data, the objective of the current study was to better define the role of perioperative radiotherapy (RT) in various SFT presentations by location.

Methods

This was retrospective study performed across 7 sarcoma centers. Clinical information was retrieved from all adult patients with extrameningeal, primary, localized SFT who were treated between 1990 and 2018 with surgery alone (S) compared with those who also received perioperative RT (S+RT). Differences in treatment characteristics between subgroups were tested using analysis of variance statistics and propensity score matching. Local control and overall survival rates were calculated from the start of treatment until progression or death from any cause.

Results

Of all 549 patients, 428 (78%) underwent S, and 121 (22%) underwent S+RT. The median follow‐up was 52 months. After correction for mitotic count and surgical margins, S+RT was significantly associated with a lower risk of local progression (hazard ratio, 0.19: P = .029), an observation further confirmed by propensity score matching (P = .012); however, this association did not translate into an overall survival benefit.

Conclusions

The results from this retrospective study investigating perioperative RT in patients with primary extrameningeal SFT suggest that combining RT with surgery in the management of this patient population is significantly associated with a reduced risk of local failures, especially in patients who have less favorable resection margins and in those who have tumors with a high mitotic count.

This retrospective study of perioperative radiotherapy in patients with primary extrameningeal solitary fibrous tumors suggests that combining radiotherapy with surgery in the management of this population significantly reduces the risk of local failures, especially in patients who have less favorable resection margins or tumors with a high mitotic count.

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

BACKGROUND AND PURPOSE

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

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Surgery plus adjuvant radiotherapy for primary central nervous system lymphoma

Objective: Recent studies of primary central nervous system lymphoma (PCNSL) have found a positive association between cytoreductive surgery and survival, challenging the traditional notion that surgery is not beneficial and potentially harmful. However, no studies have examined the potential added benefits of adjuvant treatment in the post-operative setting. Here, we investigate survival in PCNSL patients treated with surgery plus radiation therapy (RT).Methods: The Surveillance, Epidemiology, and End-Results Program was used to identify patients with PCNSL from 1995-2013. We retrospectively analyzed the relationship between treatment, prognostic factors, and survival using case-control design. Treatment categories were compared to biopsy alone.Results: We identified 5417 cases. Median survival times for biopsy alone (n = 1824, 34%), biopsy + RT (n = 1460, 27%), surgery alone (n = 1222, 27%), and surgery + RT (n = 911, 17%) were 7, 8, 20, and 27 months, respectively. On multivariable analysis, surgery + RT was associated with improved survival over surgery alone (hazard ratio [HR] = 0.58 [95% confidence interval = 0.53-0.64] vs. HR = 0.71 [0.65-0.77]). Adjuvant RT was associated with improved survival, regardless of the extent of resection. HR's for subtotal resection, gross-total resection, subtotal resection + RT, and gross-total resection + RT were 0.77 (0.66-0.89), 0.66 (0.57-0.76), 0.62 (0.52-0.72), and 0.54 (0.46-0.63), respectively. Survival improved after adjuvant RT in patients under and over 60 years old. All findings were confirmed by multivariable analysis of cause-specific survival.Conclusion: Adjuvant RT was associated with improved survival in PCNSL patients who underwent surgery. Although these data are hypothesis-generating, additional information on neurotoxicity, dosing, and concurrent chemotherapy will be necessary to validate these findings. Cytoreductive surgery for PCNSL is common in the general population, and more studies are needed to assess optimal treatment in the post-operative setting.

Clear Cell Adenocarcinoma of the Urinary Bladder Is a Glycogen-Rich Tumor with Poorer Prognosis

Clear cell adenocarcinoma (CCA) is a rare variant of urinary bladder carcinoma with a glycogen-rich phenotype and unknown prognosis. Using the National Cancer Institute's surveillance, epidemiology, and end results (SEER) program database, we documented recent trends in incidence, mortality, demographical characteristics, and survival on this rare subtype of urinary bladder cancer. The overall age-adjusted incidence and mortality of CCA was 0.087 (95% confidence interval (CI): 0.069-0.107) and 0.064 (95% CI: 0.049-0.081) respectively per million population. In comparison to non-CCAs, CCAs were more commonly associated with younger age (<60 years old, p = 0.005), female (p < 0.001), black ethnicity (p = 0.001), grade III (p < 0.001), and higher AJCC 6th staging (p < 0.001). In addition, CCA patients more frequently received complete cystectomy (p < 0.001) and beam radiation (p < 0.001) than non-CCA patients. Our study showed a poorer prognosis of CCAs compared to all other carcinomas of the urinary bladder (p < 0.001), accounted for by higher tumor staging of CCA cases. This study adds to the growing evidence that glycogen-rich cancers may have unique characteristics affecting tumor aggressiveness and patient prognosis. Additional mechanistic studies are needed to assess whether it's the excess glycogen that contributes to the higher stage at diagnosis.

Extent of resection and survival for oligodendroglioma: a U.S. population-based study

BACKGROUND

National guidelines recommend maximal safe resection of low-grade and high-grade oligodendrogliomas. However, there is no level 1 evidence to support these guidelines, and recent retrospective studies on the topic have yielded mixed results.

OBJECTIVE

To assess the association between extent of resection (EOR) and survival for oligodendrogliomas in the general U.S.

POPULATION

METHODS

Cases diagnosed between 2004 and 2013 were selected from the Surveillance, Epidemiology, and End-Results (SEER) Program and retrospectively analyzed for treatment, prognostic factors, and survival times. Cases that did not undergo tumor de-bulking surgery (e.g. no surgery or biopsy alone) were compared to subtotal resection (resection) and gross-total resection (GTR). The primary end-points were overall survival (OS) and cause-specific survival (CSS). An external validation cohort with 1p/19q-codeleted tumors was creating using the TCGA and GSE16011 datasets.

RESULTS

3135 Cases were included in the final analysis. The 75% survival time (75ST) and 5-year survival rates were 47 months and 70.8%, respectively. Subtotal resection (STR, 75ST = 50 months) and GTR (75ST = 61 months) were associated with improved survival times compared to cases that did not undergo surgical debulking (75ST = 20 months, P < 0.001 for both), with reduced hazard ratios (HRs) after controlling for other factors (HR 0.81 [0.68-0.97] and HR 0.65 [0.54-0.79], respectively). GTR was associated with improved OS in both low-grade and anaplastic oligodendroglioma subgroups (HR 0.74 [0.58-0.95], HR 0.60 [0.44-0.82], respectively) while STR fell short of significance in the subgroup analysis. All findings were corroborated by multivariable analysis of CSS and externally validated in a cohort of patients with 1p19q-codeleted tumors.

CONCLUSION

Greater EOR is associated with improved survival in oligodendrogliomas. Our findings in this U.S. population-based cohort support national guidelines.

Large-Cell Neuroendocrine Carcinoma of the Lung: A Population-Based Study

INTRODUCTION

Large-cell neuroendocrine carcinoma (LCNEC) accounts for approximately 3% of lung malignancies. There are limited data on the epidemiology and best treatment practices for this malignancy. This study aimed to be the largest cohort with the most up-to-date analysis of the epidemiology of LCNEC.

PATIENTS AND METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was queried to identify cases of LCNEC diagnosed from 2010 through 2015, reflecting years the American Joint Committee on Cancer 7th edition staging system was in use. Using these data, we compared the epidemiology, demographics, clinical characteristics, and survival times of LCNEC with small-cell lung carcinoma (SCLC) and non-SCLC (NSCLC). Trends in incidence and mortality were recorded from 2004 to 2015.

RESULTS

A total of 195,148 cases of lung cancer, including 1681 (0.9%) cases of LCNEC, were analyzed. LCNEC was more common among male subjects, and disease usually presented at stage IV (55%). Brain metastasis occurred more frequently in LCNEC (19.2%) than SCLC (16.7%, P < .001) or NSCLC (13%, P < .001). Incidence increased by 0.011 people per 100,000 per year, primarily of stage IV disease. Annual mortality from LCNEC doubled over the time period studied. Survival in patients with stage I-III LCNEC mirrored survival trends of patients with NSCLC, whereas stage IV LCNEC behaved similarly to SCLC.

CONCLUSION

LCNEC generally presents at more advanced stages than NSCLC but earlier than SCLC. Stage I-III LCNEC behaves similarly to NSCLC, whereas stage IV is more akin to SCLC. LCNEC incidence is increasing. Despite this, it remains poorly studied and did not demonstrate an improved prognosis in our cohort.