Prognostic Factors in Patients with Primary Hemangiopericytomas of the Central Nervous System: A Series of 103 Cases at a Single Institution

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.

A Single-Center Retrospective Analysis of Intracranial and Spinal Solitary Fibrous Tumor/Hemangiopericytoma Clinical Outcomes: Sex Association With Aggressiveness

BACKGROUND

Solitary fibrous tumor/hemangiopericytoma (SFT/HPCT) is a rare tumor characterized by high recurrence rate and metastatic potential, even after surgical resection. We report on the clinical outcomes and risk factors for metastasis and progression-free survival (PFS) of patients diagnosed with SFT/HPCT.

METHODS

We retrospectively identified patients with intracranial or spinal SFT/HPCT who underwent surgical resection and/or radiation therapy at our institution between 1995 and 2021. Baseline demographics, tumor characteristics, and outcome data were collected, and factors associated with PFS and metastasis were analyzed.

RESULTS

Thirty-four subjects (mean age, 46.4 years; 44% female) with a histopathologically proven diagnosis of SFT/HPCT were included; the median follow-up was 89.7 months. Twenty-two tumors were supratentorial (67%), 6 (18%) were infratentorial, and 5 (15%) were spinal. Eleven patients had documented occurrence of metastasis (32%). Detailed preoperative and postoperative data were available for 25 patients (74%) who received treatment at our institution after their initial diagnosis. Of those, 20 (80%) underwent gross total resection (GTR), and 12 (48%) received either adjuvant or salvage radiotherapy. Univariate analyses revealed that males had a shorter mean PFS compared with females (25 months vs. 78 months; P = 0.01), and that patients who underwent GTR had a longer mean PFS compared with those who underwent subtotal resection (54 months vs. 23 months; P = 0.02). Male sex was the sole risk factor for metastasis (odds ratio, 6.75; 95% confidence interval, 1.19-38.02).

CONCLUSIONS

Our data demonstrate a strong association between male sex and the outcomes of shorter PFS and higher risk for metastases. Further research is warranted to understand the clinical characteristics and outcomes of this rare tumor.

A Rare Case of a Primary Leiomyoma of the Clivus in an Immunocompetent Patient and a Review of the Literature Regarding Clival Lesions

Leiomyomas are common lesions that are usually located in the genitourinary and gastrointestinal tracts. Primary leiomyomas at the skull base are uncommon. They are composed of well-differentiated smooth muscle cells without cellular atypia. The diagnosis of a leiomyoma has to be confirmed by immunohistochemistry. The tumor tissue is immunoreactive for SMA, S100 and cytokeratin. Leiomyomas mainly occur in immunocompromised patients. Most tumor tissues are positive for EBV. The presented case is that of a 56-year-old immunocompetent woman with a tumor on the clivus. The radiological images suggested chordoma or fibrous dysplasia. Transnasal transsphenoidal surgery was performed. The tumor tissue consisted of well-differentiated smooth muscle cells with elongated nuclei. Immunohistochemistry revealed a positive reaction for desmin, SMA and h-Caldesmon and a negative reaction for S100, beta-catenin, PGR and Ki67. The leiomyoma diagnosis was subsequently established. To the best of our knowledge, the case of a primary leiomyoma on the clivus of an immunocompetent patient is the first to be described. We also extensively reviewed the literature on the immunohistopathological and radiological differential diagnosis of clival lesions.

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.

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.

The risks factor of recurrence after skull base hemangiopericytoma management: A retrospective case series and review of literature

OBJECTIVES

Skull base hemangiopericytomas are rare malignant meningothelial tumors involving anterior, middle, and posterior cranial fossa. The outcome of these tumors is inferior due to aggressive behavior and local recurrence. The study aimed to find out the factors affecting the early recurrence and the late recurrence.

METHODOLOGY

A retrospective study was performed over 15 years, and patients were included from a single neurosurgical unit. A total of 35 patients were recruited for analysis.

RESULTS

Twenty-five (71.4%) cases were in the posterior fossa, four (11.4%) cases in the middle cranial fossa, and three (8.6%) patients in the anterior cranial fossa. Fourteen (40%) cases underwent gross total excision, 21(60%) cases subtotal excision. Follow up available for 32 patients, and the median follow -up duration was 64 months (6-240 months). Progression-free survival for the gross total resection group was 104 months compared to 60 months for subtotal resection (p = 0.07). Nineteen (54.3%) cases had recurrence during follow- up period. Six (17.1%) cases recurrence at 1-year time, five (14.3%) cases at 3-year time, three (8.6%) at 5-yr time, four (11.4%) cases at 10- year time. Seventeen (48.6%) cases received radiotherapy, and 13 cases underwent re-exploration and excision of the tumor. Univariate ordinal logistic regression showed that the extent of resection was associated with 1-year, 3-year and 5-year recurrence. Multivariate ordinal logistic regression showed that only extent of resection (STR) was associated with both early and late recurrence.

CONCLUSIONS

The extent of resection is the main predictor of early and delayed recurrence. Upfront radiation therapy has superior tumor control in skull base location.

The Role of Postoperative Radiotherapy in Intracranial Solitary Fibrous Tumor/Hemangiopericytoma: A Multi-Institutional Retrospective Study (KROG 18-11)

Purpose

To evaluate the role of postoperative radiotherapy (PORT) in intracranial solitary fibrous tumor/hemangiopericytoma (SFT/HPC).

Methods and Materials

A total of 133 patients with histologically confirmed HPC were included from 8 institutions. Gross total resection (GTR) and subtotal resection (STR) were performed in 86 and 47 patients, respectively. PORT was performed in 85 (64%) patients. The prognostic effects of sex, age, performance, WHO grade, location, size, Ki-67, surgical extent, and PORT on local control (LC), distant metastasis-free survival (DMFS), progression-free survival (PFS), and overall survival (OS) were estimated by univariate and multivariate analyses.

Results

The 10-year PFS, and OS rates were 45%, and 71%, respectively. The multivariate analysis suggested that PORT significantly improved LC (p<0.001) and PFS (p<0.001). The PFS benefit of PORT was maintained in the subgroup of GTR (p=0.001), WHO grade II (p=0.001) , or STR (p<0.001). In the favorable subgroup of GTR and WHO grade II, PORT was also significantly related to better PFS (p=0.028). WHO grade III was significantly associated with poor DMFS (p=0.029). In the PORT subgroup, the 0-0.5 cm margin of the target volume showed an inferior LC to a large margin with 1.0-2.0 cm (p=0.021). Time-dependent Cox proportion analysis showed that distant failures were significantly associated with poor OS (p=0.003).

Conclusion

This multicenter study supports the role of PORT in disease control of intracranial SFT/HPC, irrespective of the surgical extent and grade. For LC, PORT should enclose the tumor bed with sufficient margin.

The Importance of STAT6 in a Schwannoma-like Grade III Solitary Fibrous Tumor/Hemangiopericytoma Located in the Cerebellopontine Angle and Meckel's Cave

BACKGROUND

Hemangiopericytoma (HPC) is a rare mesenchymal tumor of the brain that occurs in the central nervous system as a solitary fibrous tumor. Surgical treatment of HPC is known to be beneficial, but results on the role of complete resection and adjuvant radiation are conflicting. However, it is often difficult to detect a central nervous system solitary fibrous tumor/HPC before surgery. We describe a presumed left trigeminal schwannoma that was histopathologically shown to be an HPC.

CASE DESCRIPTION

A 65-year-old man presented with paresthesia of the second and third branches of the left trigeminal nerve. Magnetic resonance imaging showed a tumoral lesion in the left cerebellopontine angle and Meckel's cave. We suspected a schwannoma and performed surgery, which resulted in only a partial resection because of tumor bleeding and unexpected intraoperative histologic findings. We could not achieve a definitive diagnosis. However, we observed local recurrence and disseminated lesions 5 and 6.5 years later, respectively. We performed a second surgery and were able to definitively diagnose the lesion as a grade III HPC based on the positive expression of STAT6 during immunostaining.

CONCLUSIONS

As solitary fibrous tumor/HPC requires gross total resection for effective resolution, it is imperative to consider it in the differential diagnoses of similar tumors. If an unusual pathologic image is found, we recommend rapid immunostaining for STAT6 to reach a definitive conclusion regarding the tumor type. This case highlights the importance of considering HPC when screening or diagnosing central nervous system lesions, especially in this rare location.

Intracranial Meningeal Hemangiopericytomas: An Analysis of Factors Affecting Outcome in 39 Cases Managed with Multimodality Treatment

Aim

To retrospectively evaluate the outcome of patients with intracranial meningeal hemangiopericytomas (MHPCs) and to analyze various factors for recurrence and survival in these patients.

Materials and Methods

We retrospectively reviewed the clinical data of 39 patients undergoing microsurgical resection for MHPCs at our institute from 2009 to 2015.

Results

Gross total excision (GTE) was achieved in 27 (69.2%) patients, whereas 12 (30.8%) underwent subtotal excision (STE). A total of 25 patients received radiotherapy (RT) (Conventional RT-15; GKT-10), 21 patients had a low grade tumor, while 18 had an anaplastic variant. Twenty patients (51.3%) developed recurrences and the average recurrence-free survival (RFS) was 56 months (range: 12-180 months). Eight patients (20.5%) died during the study period. The average overall survival (OS) was 77.2 months (range: 36-192 months). Two patients (5.1%) developed systemic metastases during follow-up. Patient age was not found to affect RFS or OS. GTE was associated with prolonged RFS and OS but the impact was not statistically significant (P-values = 0.160 and 0.414, respectively). Low tumor grade was associated with statistically significant longer RFS as well as OS (P-values = 0.049 and 0.013, respectively). Addition of adjuvant RT was associated with statistically significant prolongation of RFS (P value = 0.016); however, it was not associated with statistically significant OS benefits (P-value = 0.758).

Conclusions

Our study suggests that a greater extent of excision, lower tumor grade, and addition of adjuvant RT have a positive impact on both RFS and OS; however, low grade and adjuvant RT were the only factors associated with statistically significant prolongation of RFS and only tumor grade was associated with statistically significant OS benefits.

Metastatic craniocervical hemangiopericytoma presenting with hydrocephalus and papilledema - Case review

Hemangiopericytomas are rare mesenchymal tumors with propensity to recur locally and metastasize. We report the unique case of a fifty-five-year-old male with recurrence of a previously resected craniocervical hemangiopericytoma presenting with obstructive hydrocephalus secondary to new metastatic cerebellar deposits. Emergent surgical resection of the cerebellar hemangiopericytomas was performed prior to adjuvant radiotherapy. Hemangiopericytomas are rare but important differentials for craniocervical junction lesions. Gross total resection remains the cornerstone of management with post-operative radiotherapy and chemotherapy as potential adjuncts. Tumors located in deep regions pose complex management challenges as safe maximal excision may be limited by proximal eloquent structures.

Atypical epidural hemangiopericytoma presenting with visual disturbance

Background:

Hemangiopericytomas are a rare entity commonly presenting as subdural tumors.

Case Description:

A 57-year-old man presented with a progressive visual disturbance over a period of 3 weeks. Cranial computed tomography scans revealed an isodense mass at the tip of the left middle fossa, extending into the orbital apex, and accompanying bony erosions in the sphenoid ridge. On magnetic resonance imaging, the lesion appeared isointense both on T1- and T2-weighted sequences, and intensely enhanced on contrast examinations. A frontotemporal craniotomy revealed a dura-based, capsulized tumor located entirely in the epidural space. A gross total resection was achieved for the tumor and histologically verified as hemangiopericytoma.

Conclusion:

Hemangiopericytoma should be assumed in a differential diagnosis when encountering epidural tumors, and total resection should be attempted when possible.