Primary intracranial soft tissue sarcomas in children, adolescents, and young adults: single institution experience and review of the literature

Primary intracranial dedifferentiated liposarcoma: An extremely rare site with unusual histopathological findings

Primary intracranial sarcomas constitute a rare group of tumors, with the most common types described in the literature being chondrosarcoma and fibrosarcoma. Dedifferentiated liposarcoma (DDLS) is a high-grade sarcoma that sometimes metastasizes to the brain. However, a primary intracranial DDLS is exceedingly rare. A 45-year-old patient from the Middle East came to India for treatment. His magnetic resonance imaging (MRI) scans revealed a space-occupying lesion at the level of the lateral ventricle T2/fluid attenuated inversion recovery hyperintensity with peripheral edema. A T1 perfusion map showed high relative cerebral blood volume values in the peripheral part, suggesting a high-grade neoplasm. Gross total resection was performed, and histopathology showed a high-grade tumor composed of sheets of pleomorphic lipoblasts and epithelioid tumor cells arranged in nests and cords. Immunohistochemistry showed diffuse immunopositivity for MDM2, CDK4, and p16, while GFAP and OLIG2 were negative. Fluorescence in situ hybridization showed MDM2 amplification. Final diagnosis of DDLS was rendered. The patient had no systemic lesions elsewhere on positron emission tomography computed tomography scan.

Increase of primary intracranial sarcoma in children: Clinical manifestations, diagnosis, and management

Background

Primary intracranial sarcomas (PISs) are very rare malignant tumors, and there is paucity of data on it, exclusively in patients <18 years old. We report pediatric PIS at a tertiary hospital in Peru, where the incidence of PIS has increased in recent years.

Methods

We retrospectively analyzed data in children diagnosed with PIS based on clinical presentation, imaging studies, and histopathology between January 2020 and December 2023.

Results

Twenty-five cases were identified. The median age was 5 years. There is slight female predominance (56%). On presentation, 68% of patients had features of intracranial hypertension (ICH), others had convulsions or motor deficits. There was radiologic evidence of cerebral hemorrhage in 80% of those with features of ICH and convulsion. All but one case had a supratentorial tumor. Emergency craniotomy was done in 84% of cases, and gross total resection (GTR) was achieved in the first surgery in 72% of cases. We used an adjuvant chemotherapyradiotherapy-chemotherapy (CTX-RT-CTX) regimen in 72% of cases, but 12% started this scheme 2 weeks after surgical resection. The cases followed up for more than a year that were managed with CTX-RT-CTX after GTR had a survival greater than a year, compared to the cases that received complementary treatment after 4 weeks.

Conclusion

PIS among children represents an infrequent pathology that, in the last years, its incidence has increased in Peru. The presence of intracerebral hemorrhage is a very suggestive finding of this diagnosis; therefore, emergent surgical management is an option before an irreversible ICH presents. Adjuvant treatment with the CTX-RT-CTX regimen started 2 weeks after GTR may improve survival in children with PIS.

Recurrent primary intracranial sarcoma, DICER1-mutant in a pediatric patient with DICER1 syndrome: the importance of molecular testing

Pediatric intracranial sarcomas are rare, aggressive tumors with a poor prognosis in general. Here we report the case of a child who was initially diagnosed with a primary intracranial sarcoma, DICER1-mutant; subsequent genetic analyses confirmed a pathogenic germline DICER1 mutation. She received multimodal standard treatments consisting of surgery, radiotherapy and chemotherapy. The tumor recurred 2.5 years later within the surgical cavity. Following the gross tumor resection of this new lesion, the same multimodal standard approach was used. From a molecular perspective, evidence of hyperactivation of the MAPK-kinase pathway with a pathogenic KRAS mutation at both diagnosis and recurrence was present. The patient is currently in remission, 18 months post-end of treatment.

Clinical presentation of childhood soft tissue sarcomas: a systematic review and meta-analysis

BACKGROUND

Time to diagnosis (TTD) of childhood soft tissue sarcoma (STS) is significantly associated with survival. This review aims to identify pre-diagnostic symptoms/signs to inform earlier diagnosis interventions.

METHODS

Medline, Embase, Cochrane and Web-of-Science were searched between January 2010 and February 2021 for studies including children (<18 years) diagnosed with STS, with no language restrictions. Pooled proportions of symptoms/signs were calculated and subanalysed by tumour location and age.

RESULTS

Fifty-nine eligible studies were identified, totalling 2462 cases. The most frequent symptoms were lump/swelling (38%, 95% CI 27% to 51%), pain (6%, 95% CI 3% to 10%), cutaneous changes (4%, 95% CI 0 to 9%), localised eye swelling (3%, 95% CI 0 to 7%), cranial nerve deficits (2%, 95% CI 0 to 5%) and constitutional symptoms (2%, 95% CI 0 to 5%).Symptoms varied by location and age. Localised eye swelling (20%, 95% CI 3% to 45%), cranial nerve deficits (14%, 95% CI 4% to 28%) and impaired visual function (6%, 95% CI 0 to 17%) were frequent in head and neck tumours. For abdomen/pelvic tumours, urinary symptoms (24%, 95% CI 5% to 15%), abdominal distension/discomfort (22%, 95% CI 4% to 47%), genital lump/swelling (16%, 95% CI 1% to 42%), constitutional symptoms (9%, 95% CI 0%] to 23%), vaginal bleeding (7%, 95%C I 0 to 21%) and bowel habit changes (6%, 95% CI 0 to 17%) were frequent.In <5 years, consumptive coagulopathy (16%, 95% CI 0 to 48%), cutaneous changes (5%, 95% CI 0 to 40%), genital lump/swelling (4%, 95% CI 0 to 14%), reduced mobility (3%, 95% CI 0 to 11%), vaginal bleeding (2%, 95% CI 0 to 11%) and bleeding/bruising/petechiae (2%, 95% CI 0 to 20%) were frequent compared with lump/swelling, constitutional symptoms, pain and headaches which were frequent among >11 years.

CONCLUSIONS

For STS, pre-diagnostic symptoms differ by age and location, highlighting the need to tailor early diagnosis interventions.

Characteristics and therapeutic strategies of brain and cranial radiation-induced sarcoma: analysis of 165 cases from our case experience and comprehensive review

BACKGROUND

Radiation-induced sarcoma (RIS) is among the neoplasms potentially caused by radiation therapy (RT) for brain tumors. However, the clinical characteristics of and ideal treatment for RIS are unclear. We analysed our case experience and conducted a comprehensive literature review to reveal the characteristics of brain and cranial RIS.

METHODS

We analysed 165 cases of RIS from the literature together with the RIS case treated at our institution. In each case, the latency period from irradiation to the development of each RIS and the median overall survival (OS) of the patients was analysed by Kaplan-Meier analysis. Spearman's correlation test was used to determine the relationship between the latency period and radiation dose or age at irradiation.

RESULTS

The mean age at the development of RIS was 39.63 ± 17.84 years. The mean latency period was 11.79 ± 8.09 years. No factors associated with early development of RIS were detected. The median OS was 11 months, with fibrosarcoma showing significantly shorter OS compared with osteosarcoma and other sarcomas (p = 0.0021), and intracranial RIS showing a worse prognosis than extracranial RIS (p < 0.0001). Patients treated with surgery (p < 0.0001) and postoperative chemotherapy (p = 0.0157) for RIS presented significantly longer OS, whereas RT for RIS was not associated with a survival benefit.

CONCLUSIONS

Although prognosis for RIS is universally poor, pathological characteristics and locations are associated with worse prognosis. Surgery and chemotherapy may be the ideal treatment strategies for RIS.

Primary intracranial sarcoma masquerading as a chronic subdural haematoma: illustrative case and review of an unusual phenomenon

It is very unusual for a primary intracranial malignancy to present as a chronic subdural hematoma. This case report describes one such case in a 3-year-old girl who presented with raised intracranial pressure following a mild head injury. Imaging of her brain revealed bilateral chronic subdural hematomas with an enhancing subdural mass and multiple nodular lesions infiltrating the brain parenchyma. She underwent a craniotomy, drainage of the subdural collections and resection of the subdural mass. Histopathology revealed an undifferentiated sarcoma, and she was referred for adjuvant therapy. This case underlines the importance of evaluating paediatric subdural collections for a possible underlying malignancy, even in the background of a preceding head injury. The cause-effect relationship of sarcomas with subdural collections remains unclear because of the scarcity of available literature on the subject.

MRI findings of primary intracranial sarcomas in children

BACKGROUND

Primary intracranial sarcoma is a very rare high-grade tumor. Scant reports exist on this malignancy in children, which limit the information about its imaging characteristics.

OBJECTIVE

We aimed to describe the main characteristics of primary intracranial sarcoma on MRI.

MATERIALS AND METHODS

In this cross-sectional descriptive observational study, we reviewed 18 patients (aged 1-18 years) with primary intracranial sarcomas diagnosed between 2015 and 2021.

RESULTS

The main findings were contrast enhancement (100%), diffusion restriction (78%), hemorrhage (89%), meningeal extension (67%), necrosis (67%), and supratentorial location (72%).

CONCLUSION

Primary intracranial sarcoma are typically supratentorial in location. MRI findings of primary intracranial sarcoma are similar to other intracranial malignancies.

Primary intracranial sarcomas: a clinicopathological investigation

Background

The purpose of this study is to present a series of primary intracranial sarcomas (PIS), a rare type of tumor of the central nervous system, in order to improve our understanding of the disease. These tumors are heterogeneous and prone to recurrence after resection, exhibiting a high mortality rate. As PIS has yet to be understood and studied on a large scale, it is vital for further evaluation and research.

Methods

Our study included 14 cases of PIS. The patients' clinical, pathological, and imaging features were retrospectively analyzed. Additionally, targeted DNA next-generation sequencing (NGS) was applied for the 481-gene panel to detect gene mutations.

Results

The average age for PIS patients was 31.4 years. Headache (7, 50.0%) was the most common symptom leading to the hospital visit. Twelve cases had PIS located in the supratentorial area and two in the cerebellopontine angle region. The maximum tumor diameter ranged from 19.0 mm to 130.0 mm, with an average diameter of 50.3 mm. Pathological types of tumors were heterogeneous, with chondrosarcoma being the most common, followed by fibrosarcoma. Eight of the 10 PIS cases that underwent MRI scanning showed gadolinium enhancement; 7 of these cases were heterogeneous, and 1 of them was garland-like. Targeted sequencing was performed in two cases and identified mutations in genes such as NRAS, PIK3CA, BAP1, KDR, BLM, PBRM1, TOP2A, DUSP2, and CNV deletions of SMARCB1. Additionally, the SH3BP5::RAF1 fusion gene was also detected. Of the 14 patients, 9 underwent a gross total resection (GTR), and 5 chose subtotal resection. Patients who underwent GTR displayed a trend toward superior survival. Among the 11 patients with available follow-up information, one had developed lung metastases, three had died, and eight were alive.

Conclusion

PIS is extremely rare compared to extracranial soft sarcomas. The most common histological type of intracranial sarcoma (IS) is chondrosarcoma. Patients who underwent GTR of these lesions showed improved survival rates. Recent advancements in NGS aided in the identification of diagnostic and therapeutic PIS-relevant targets.

Primary central nervous system sarcoma with DICER1 mutation-treatment results of a novel molecular entity in pediatric Peruvian patients

BACKGROUND

A high frequency of primary central nervous system (CNS) sarcomas was observed in Peru. This article describes the clinical characteristics, biological characteristics, and outcome of 70 pediatric patients.

METHODS

Data from 70 pediatric patients with primary CNS sarcomas diagnosed between January 2005 and June 2018 were analyzed. DNA methylation profiling from 28 tumors and gene panel sequencing from 27 tumors were available.

RESULTS

The median age of the patients was 6 years (range, 2-17.5 years), and 66 of 70 patients had supratentorial tumors. DNA methylation profiling classified 28 of 28 tumors as primary CNS sarcoma, DICER1 mutant. DICER1 mutations were found in 26 of 27 cases, TP53 mutations were found in 22 of 27 cases, and RAS-pathway gene mutations (NF1, KRAS, and NRAS) were found in 19 of 27 tumors, all of which were somatic (germline control available in 19 cases). The estimated incidence in Peru was 0.19 cases per 100,000 children (<18 years old) per year, which is significantly higher than the estimated incidence in Germany (0.007 cases per 100,000 children [<18 years] per year; P < .001). Patients with nonmetastatic disease (n = 46) that were treated with a combination therapy had a 2-year progression-free survival (PFS) rate of 58% (95% CI, 44%-76%) and a 2-year overall survival rate of 71% (95% CI, 57%-87%). PFS was the highest in patients treated with chemotherapy with ifosfamide, carboplatin, and etoposide (ICE) after upfront surgery followed by radiotherapy and ICE (2-year PFS, 79% [59%-100%], n = 18).

CONCLUSIONS

Primary CNS sarcoma with DICER1 mutation has an aggressive clinical course. A combination of surgery, chemotherapy, and radiotherapy seems beneficial. An underlying cancer predisposition syndrome explaining the increased incidence in Peruvian patients has not been identified so far.

LAY SUMMARY

A high incidence of primary pediatric central nervous system sarcomas in the Peruvian population is described. Using sequencing technologies and DNA methylation profiling, it is confirmed that these tumors molecularly belong to the recently proposed entity "primary central nervous system sarcomas, DICER1 mutant." Unexpectedly, DICER1 mutations as well as all other defining tumor mutations (TP53 mutations and RAS-pathway mutations) were not inherited in all 19 patients where analyzation was possible. These tumors have an aggressive clinical course. Multimodal combination therapy based on surgery, ifosfamide, carboplatin, and etoposide chemotherapy, and local radiotherapy leads to superior outcomes.

Malignant Intracerebral Nerve Sheath Tumor Presenting With Intratumoral Hemorrhage

BACKGROUND

Primary central nervous system sarcomas are rare primitive mesenchymal non-meningothelial tumors. Malignant peripheral nerve sheath tumor accounts for 5% of sarcomas, with an incidence of approximately 0.001% and a recognized association with neurofibromatosis type 1. Its intracranial subtype, the so-called malignant intracerebral nerve sheath tumor (MINST), is even more infrequent. Current knowledge about its clinical presentation and best therapeutic management is poor because of the limited number of cases reported in literature. Commonly, intratumoral hemorrhage occurs at the time of diagnosis and, notably, most patients had intracranial hemorrhage prior to definitive diagnosis.

CASE DESCRIPTION

We report a case of MINST in a young boy affected by neurofibromatosis type 1 who presented a spontaneous intracranial hemorrhage, successfully treated with surgery and postoperative adjuvant therapy. The tumor relapsed 1 year after and was successfully retreated with a second surgery.

CONCLUSIONS

Malignant intracerebral nerve sheath tumors are rare sarcomas that can be associated with intratumoral hemorrhage at the time of presentation, mostly in patients with neurofibromatosis type 1. Surgery promptly performed, associated with adjuvant therapy, can result in an encouraging survival rate.

Myxoid mesenchymal intraventricular brain tumour with EWSR1-CREB1 gene fusion in an adult woman

Myxoid mesenchymal tumours harbouring fusions between EWSR1 and the CREB family transcription factors have recently been described. Whether they represent a novel entity or a myxoid variant of angiomatoid fibrous histiocytoma (AFH) remains a matter of debate. We describe the case of a 58-year-old woman with a previous history of breast cancer that developed progressive neurological decline due to a large mass located in the left lateral ventricle of the brain. Histology revealed a mesenchymal tumour with multinodular growth, variable cellularity, prominent myxoid stroma and numerous amianthoid fibres. No evidence of pseudo-capsule or lymphoid cuffing was identified. RNA sequencing disclosed EWSR1-CREB1 gene fusion. Only 20 cases of intracranial mesenchymal tumours harbouring these translocations have been described, mostly in adolescents and young adults and with dural attachment. Occurrence in this age group and with intraventricular location has been even more rarely reported. A better understanding of tumour behaviour is needed to establish treatment guidelines and improve patient outcome.

Intracranial Extra-axial Undifferentiated Pleomorphic Sarcoma; a Case Report

Introduction

Head-and-neck sarcomas result in high mortality rates. A lot of new cases of sarcomas are diagnosed every year constituting about 1 % of all head-and-neck malignancies. Undifferentiated pleomorphic sarcomas (UPSs) are high-grade soft-tissue malignant tumours which occur primarily in limbs and retroperitoneal cavities. These tumours can often metastasize to the central nervous system. However, in rare instances, soft-tissue sarcomas may develop as a primary lesion within the intracranial compartments.

Case Description

A young male presented to the clinic with occipital headache and blurring of vision. Initial workup included brain contrast-enhanced computed tomography (CECT) and magnetic resonance imaging (MRI). The CECT suggested that there was an extra-axial mass present which was pressing against the adjacent left frontal lobe. Overlying frontal bone of the left side showed remodelling effect and associated mild periosteal reaction. MRI scan showed intracranial extra-axial lobulated mass with T1 intermediate to low-signal intensity and intermediate to high signals on T2 sequences. Heterogeneous enhancement on post-contrast sequences was also seen. The lesion had a broad-based attachment with dura mater and was closely applied to the orbital roof without orbital invasion. Staging positron emission tomography-CT scan showed a solitary site of disease in an intracranial location. Final diagnosis was confirmed by histopathology following excision of mass as UPS. Post-surgery MRI brain showed satisfactory post-operative appearance without any residual disease. The patient remained asymptomatic for 2 years and 6 months following the resection of the tumour.

Practical Implications

Most of the extra-axial intracranial soft-tissue tumours arise from the meninges with meningiomas making the substantial bulk; however, possibility of other relatively rare tumours of meningeal origin must not be ignored. Intracranial soft-tissue sarcomas mostly arise from meninges thus require a good understanding of clinical presentation as well as acquaintance with morphological features on radiological imaging to differentiate from other tumours. These can be treated with excision and radiotherapy along with sequential follow-ups to look for recurrence. Tissue sampling is mandatory followed by complete staging scan in case of sarcomas to rule out possible primary or secondary disease.

Two cases of primary supratentorial intracranial rhabdomyosarcoma with DICER1 mutation which may belong to a "spindle cell sarcoma with rhabdomyosarcoma-like feature, DICER1 mutant"

Rhabdomyosarcoma is the most common soft-tissue sarcoma affecting children and adolescents. It is defined as a malignant neoplasm characterized by morphologic, immunohistochemical, ultrastructural, or molecular genetic evidence of primary skeletal muscle differentiation, usually in the absence of any other pattern of differentiation. Primary intracranial rhabdomyosarcoma (PIRMS) is an extremely rare neoplasm, with only 60 cases reported in the literature, and generally has poor prognosis with an overall survival of only 9.1 months. The DICER1 gene encodes an RNA endoribonuclease that plays a key role in gene expression regulation through the production of small RNAs. Herein, we report two cases of PIRMS with somatic DICER1 mutation showing morphological and immunohistochemical evidence of primary skeletal muscle differentiation; the two cases share common clinical features, including young age, supratentorial tumor, and onset of intratumoral bleeding. Although methylation profiling was not performed, both cases shared clinical and pathological characteristics in common with recently proposed methylation entity "spindle cell sarcoma with rhabdomyosarcoma-like features, DICER1 mutant (SCS-RMSlike-DICER1)''. Our cases provide further evidence of the link between primary intracranial sarcoma and DICER1 mutation which may form a distinct entity.