Neurosurgical treatment of subependymal giant cell astrocytomas in tuberous sclerosis complex: a series of 44 surgical procedures in 31 patients

Bleeding solitary SEGA in non-tuberous sclerosis complex adolescent: a case illustration and review of literature

Subependymal giant cell astrocytoma (SEGA) represents a benign brain tumor occurring in 5-20% of individuals diagnosed with tuberous sclerosis complex (TSC), serving as a major diagnostic criterion. The presence of SEGA in a patient often prompts consideration of TSC as a probable diagnosis, given its unique association with this disorder. Typically, only one additional major criterion or two minor criteria are necessary to fulfill the diagnostic criteria for TSC. However, in rare instances, SEGA may manifest in patients without clinical features of TSC, termed solitary SEGA. The occurrence of solitary SEGA in patients lacking both clinical manifestations of TSC and genetic confirmation is extremely rare. Furthermore, the presentation of SEGA with intratumoral bleeding is exceedingly uncommon. Here, we presented a case of bleeding solitary SEGA in non-TSC adolescent who underwent surgery and has remained free of disease for a minimum of 3 years. Genetic analysis of peripheral blood and tumor tissue yielded negative results for TSC-related mutations. While SEGA occurrence in non-TSC patients is uncommon, it remains one of the possible diagnoses of intraventricular tumors. However, comprehensive genetic and physical evaluations are imperative to confirm the TSC status and guide further investigations and follow-up appropriately.

Neurofibromatosis type1, type 2, tuberous sclerosis and Von Hippel-Lindau disease

Neurocutaneous syndromes (also known as phakomatoses) are heterogenous group of disorders that involve derivatives of the neuroectoderm. Each disease has diagnostic and pathognomonic criteria, once identified, thorough clinical examination to the patient and the family members should be done. Magnetic resonance imaging (MRI) is used to study the pathognomonic findings withing the CNS (Evans et al. in Am J Med Genet A 152A:327-332, 2010). This chapter includes the 4 most common syndromes faced by neurosurgeons and neurologists; neurofibromatosis types 1 and 2, tuberous sclerosis and Von Hippel-Lindau disease. Each syndrome has specific genetic anomaly that involves a tumor suppressor gene and the loss of inhibition of specific pathways. The result is a spectrum of cutaneous manifestations and neoplasms.

Subependymal Giant Cell Astrocytoma Apoplexy: A Case Report and Systematic Review

Subependymal giant cell astrocytoma (SEGA) is the most common intracranial tumor in tuberous sclerosis (TS) patients. The tumor generally localizes in the proximity of Monro's foramen; as it grows, it subsequently causes hydrocephalus and increases intracranial pressure (ICP). However, acute symptoms of increased ICP due to intratumoral bleeding rarely manifest in SEGA patients. We present a 27-year-old male with TS who presented due to hemorrhagic complications of SEGA with intratumoral bleeding and vitreous orbital hemorrhage. We then conducted a systematic review with four databases (PubMed, Web of Science, Google Scholar, and Cochrane) to identify similar cases using the following keywords: "Subependymal giant cell astrocytoma," "Hemorrhage," "Haemorrhage," and "Bleeding." Our review identified 12 articles reporting 14 cases of hemorrhagic complications of SEGA in addition to our case report. The median age of diagnosis was 21 (range 5-79) years with unequal gender distribution (M:F ratio, 11:4). Headache was the most presented symptom, followed by hemiparesis, seizure, altered mental status, visual deterioration, and headache accompanied by seizure. TS was seen in most of the cases (80%). Gross total resection (GTR) was achieved in 53.5% of the patients. Regarding the clinical outcome, 66.7% had a good outcome, 20% died, and 13.3% had no report of their outcomes. No tumor recurrence was seen in the cases with a reported duration of follow-up. Catastrophic presentation of SEGA apoplexy is a rare occurrence. We present a case report with a systematic review and discuss SEGA apoplexy's possible pathophysiology and outcome.

Subependymal Giant Cell Astrocytomas in Tuberous Sclerosis Complex-Current Views on Their Pathogenesis and Management

Introduction, Tuberous sclerosis complex (TSC) is an autosomal-dominant disorder caused by mutations inactivating TSC1 or TSC2 genes and characterized by the presence of tumors involving many organs, including the brain, heart, kidneys, and skin. Subependymal giant cell astrocytoma (SEGA) is a slow-growing brain tumor almost exclusively associated with TSC.

STATE OF THE ART

Despite the fact that SEGAs are benign, they require well-considered decisions regarding the timing and modality of pharmacological or surgical treatment. In TSC children and adolescents, SEGA is the major cause of mortality and morbidity.

CLINICAL IMPLICATIONS

Until recently, surgical resection has been the standard therapy for SEGAs but the discovery of the role of the mTOR pathway and the introduction of mTOR inhibitors to clinical practice changed the therapeutic landscape of these tumors. In the current paper, we discuss the pros and cons of mTOR inhibitors and surgical approaches in SEGA treatment.

FUTURE DIRECTIONS

In 2021, the International Tuberous Sclerosis Complex Consensus Group proposed a new integrative strategy for SEGA management. In the following review, we discuss the proposed recommendations and report the results of the literature search for the latest treatment directions.

EANO - EURACAN - SNO Guidelines on circumscribed astrocytic gliomas, glioneuronal, and neuronal tumors

In the new WHO 2021 Classification of CNS Tumors the chapter "Circumscribed astrocytic gliomas, glioneuronal and neuronal tumors" encompasses several different rare tumor entities, which occur more frequently in children, adolescents, and young adults. The Task Force has reviewed the evidence of diagnostic and therapeutic interventions, which is low particularly for adult patients, and draw recommendations accordingly. Tumor diagnosis, based on WHO 2021, is primarily performed using conventional histological techniques; however, a molecular workup is important for differential diagnosis, in particular, DNA methylation profiling for the definitive classification of histologically unresolved cases. Molecular factors are increasing of prognostic and predictive importance. MRI finding are non-specific, but for some tumors are characteristic and suggestive. Gross total resection, when feasible, is the most important treatment in terms of prolonging survival and achieving long-term seizure control. Conformal radiotherapy should be considered in grade 3 and incompletely resected grade 2 tumors. In recurrent tumors reoperation and radiotherapy, including stereotactic radiotherapy, can be useful. Targeted therapies may be used in selected patients: BRAF and MEK inhibitors in pilocytic astrocytomas, pleomorphic xanthoastrocytomas, and gangliogliomas when BRAF altered, and mTOR inhibitor everolimus in subependymal giant cells astrocytomas. Sequencing to identify molecular targets is advocated for diagnostic clarification and to direct potential targeted therapies.

Subependymal giant-cell astrocytoma: a surgical review in the modern era of mTOR inhibitors

INTRODUCTION

Surgical removal has been the historical treatment for subependymal giant-cell astrocytoma (SEGA) in tuberous sclerosis complex (TSC) patients. In the past decade, mTOR inhibitors have shown efficacy in the treatment of SEGA, significantly reducing tumor size. The aim of this study was to assess the safety and efficacy of surgical treatment at a time when mTOR inhibitors have changed standard treatment.

MATERIAL AND METHODS

We conducted a single-center retrospective study including all patients treated by surgery for SEGA from October 2003 to September 2019, with a review of all SEGA surgical case series, following PRISMA guidelines. Research focused on demographics, surgical indications, surgical approach, use of CSF shunt, morbidity and mortality, resection quality, recurrence rate and treatment of recurrence, follow-up and long-term clinical status.

RESULTS

Eleven patients were included, with a median age at surgery of 16.0 years. Gross total resection was achieved in 8 patients (72%), with no permanent morbidity. One patient needed further surgery for tumor recurrence. Eighteen studies were reviewed, totaling 263 TSC patients affected by SEGA and 286 surgical procedures. Gross total resection was achieved in 81.1% of cases, mortality was 4.9% and permanent morbidity 6.1%. Tumor recurrence occurred in 11.5% of cases, and was secondary to partial tumor resection at first surgery in the majority of cases.

CONCLUSION

Surgical treatment of SEGA is still a valid and effective option. Morbidity is low and complete disappearance of SEGA can be achieved in selected cases.

Optimization and high-density array of stereoelectroencephalography-guided radiofrequency thermocoagulation for the treatment of pediatric tuberous sclerosis complex with epilepsy

BACKGROUND

Tuberous sclerosis complex (TSC) is an autosomal dominant neurocutaneous syndrome involved in many organ systems. At the same time, epilepsy is the most common manifestation and more than 50% of TSC patients present with intractable epilepsy. This study investigated the efficacy and safety of optimized and high-density stereoelectroencephalography (SEEG) guided radiofrequency thermocoagulation (RF-TC) in treating TSC-related epilepsy.

METHODS

Nine TSC children with refractory epilepsy were treated with first-stage SEEG-Guided RF-TC, and four underwent second-stage-optimized high-density array of SEEG-Guided RF-TC. Patients' clinical data and postoperative outcomes were analyzed retrospectively.

RESULTS

The patients' median age at surgery was 4 years and 2 month (range from 3 years and 5 month to 16 years and 7 month). The mean age at surgery was 6.7 years old. Eight in 9 (88.9%) patients achieved complete remission after the final operation at half-year follow-up. Of seven patients with final postoperative time beyond 1 year, 6 (85.7%) reached completely seizure-free. No severe or long-term neurologic impairment existed in all nine patients.

CONCLUSION

Optimized high-density array of SEEG-guided RF-TC is a safe and highly effective approach and can be an alternative application applied for TSC patients with refractory epilepsy.

Syndromic Hydrocephalus

Hydrocephalus, the abnormal accumulation and impaired circulation/clearance of cerebrospinal fluid, occurs as a common phenotypic feature of a diverse group of genetic syndromes. In this review, we outline the genetic mutations, pathogenesis, and accompanying symptoms underlying syndromic hydrocephalus in the context of: L1 syndrome, syndromic craniosynostoses, achondroplasia, NF 1/2, Down's syndrome, tuberous sclerosis, Walker-Warburg syndrome, primary ciliary dyskinesia, and osteogenesis imperfecta. Further, we discuss emerging genetic variants associated with syndromic hydrocephalus.

Neurosurgical Considerations of Neurocutaneous Syndromes

The phakomatoses are a group of genetic and acquired disorders characterized by neurologic, cutaneous, and often ocular manifestations, thus commonly referred to as neurocutaneous syndromes. In several of these conditions the underlying genetic pathophysiology has been elucidated, which will continue to play an important role in advancing therapeutic techniques. This article focuses on several examples of such neurocutaneous syndromes, with special attention to the relevant neurosurgical considerations of these patients.

Sclerosi tuberosa ed everolimus: una nuova storia

Tuberous sclerosis complex (TSC) is a rare autosomal dominant disorder, due to inactivating muta-tions of TSC1 or TSC2 mTOR pathway genes and is characterized by variable multisystem manifestations ranging from hamartomas to malignant neoplasms. It frequently associated to seizures, intellectual disability and behavioural disorders. Surgical treatment has traditionally been used to manage subependymal giant cells astrocytomas (SEGA). The introduction of mTOR inhibitor rapamycin, with its definite role both as primary and as adjuvant treatment, has significantly modified the management opportunities in the clinical practice. It is important to consider both treatment options in a balanced way and not only the SEGA, but also the individual patient and their associated comorbidities. The pros and the cons of both options should be discussed by a multidisciplinary team before establishing an individualized treatment recommendation. The paper reports the case of a patient with an asymptomatic SEGA who was treated with everolimus. The treatment was effective in reducing the size of the tumour, it was safe and well tolerated.

Infantile Brain Tumors: A Review of Literature and Future Perspectives

Brain tumors in infants including those diagnosed in fetal age, newborns and under a year old represent less than 10% of pediatric nervous system tumors and present differently when compared with older children in terms of clinical traits, location and histology. The most frequent clinical finding is a macrocephaly but non-specific symptoms can also be associated. The prognosis is usually poor and depends on several factors. Surgery continues to be the main option in terms of therapeutic strategies whereas the role of chemotherapy is not yet well defined and radiotherapy is exceptionally undertaken. In view of this situation, a molecular characterization could assist in providing therapeutic options for these tumors. This review highlights the recent advances in the diagnosis and treatment of brain tumors in infants with a particular focus on the molecular landscape and future clinical applications.

Experience using mTOR inhibitors for subependymal giant cell astrocytoma in tuberous sclerosis complex at a single facility

BACKGROUND

Subependymal giant cell astrocytoma (SEGA) is occasionally seen in tuberous sclerosis complex (TSC). Two main options are currently available for treating SEGA: surgical resection or pharmacotherapy using mammalian target of rapamycin inhibitors (mTORi). We hypothesized that opportunities for surgical resection of SEGA would have reduced with the advent of mTORi.

METHODS

We retrospectively reviewed the charts of patients treated between August 1979 and July 2020, divided into a pre-mTORi era group (Pre-group) of patients treated before November 2012, and a post-mTORi era group (Post-group) comprising patients treated from November 2012, when mTORi became available in Japan for SEGA. We compared groups in terms of treatment with surgery or mTORi. We also reviewed SEGA size, rate of acute hydrocephalus, recurrence of SEGA, malignant transformation and adverse effects of mTORi.

RESULTS

In total, 120 patients with TSC visited our facility, including 24 patients with SEGA. Surgical resection was significantly more frequent in the Pre-group (6 of 7 patients, 86 %) than in the Post-group (2 of 17 patients, 12 %; p = 0.001). Acute hydrocephalus was seen in 1 patient (4 %), and no patients showed malignant transformation of SEGA. The group treated using mTORi showed significantly smaller SEGA compared with the group treated under a wait-and-see policy (p = 0.012). Adverse effects of pharmacotherapy were identified in seven (64 %; 6 oral ulcers, 1 irregular menstruation) of the 11 patients receiving mTORi.

CONCLUSIONS

The Post-group underwent surgery significantly less often than the Pre-group. Since the treatment option to use mTORi in the treatment of SEGA in TSC became available, opportunities for surgical resection have decreased in our facility.

Bibliometric analysis of the top 100 most-cited articles on astrocytoma

Background

Citation analysis reflects the scientific recognition and influential performance of a published article within its field. We aim to identify the top 100 most-cited articles on astrocytoma using this bibliometric analysis method.

Methods

In May 2020, we performed a thorough search in the Scopus database using the word "Astrocytoma." The top 100 most-cited articles were arranged based on citation count in descending order. The resultant articles were then analyzed with an assessment of pertinent factors.

Results

The most-cited articles on astrocytoma had been cited 23,720 times. The top-cited article received a total of 682 citations, with an average of 34.1 citations annually. The list comprised eight clinical trials, in which the highest cited article received 625 citations. Articles were published from 1975 to 2015 with the 1995-2005 era as the most prolific period. Neuropathology studies were the most studied category, followed by clinical studies. The United States of America was the most significant contributor, with 49 published articles. The University of California San Francisco was the most contributing institution by producing 11 articles. Articles were published in 32 different journals led by the Cancer Research Journal, with a total of 12 publications. Approximately 160 authors contributed to the list in which Scheithauer, B.W. contributed the most with a total of eight articles.

Conclusion

This report clustered the most impactful articles on astrocytoma. It serves as an adequate tool to identify publication trends and helps in achieving evidence-based clinical practice.

Current trends in the management of subependymal giant cell astrocytomas in tuberous sclerosis

INTRODUCTION

The management of subependymal giant cells astrocytomas (SEGAs) has been traditionally represented by surgical treatment through an open craniotomic approach. Though open surgery still represents a major option in the management of this kind of tumors, the introduction of mTOR inhibitors in the clinical practice, technological advances in neuroendoscopy and the more recent use of laser interstitial therapy have significantly enlarged the range of available management opportunities.

METHODS

A thorough review of the literature has been performed. Accordingly, current views in open surgical treatment, medical therapy, endoscopic tumor removal and new trends (such as laser interstitial thermal therapy) are discussed.

RESULTS

The risk of significant neurological morbidity (5-50%) complicating open surgery has been for a long time representing a main drawback in the management of SEGAs. More recent series report a significant reduction of morbidity and mortality. The mTOR inhibitors have demonstrated efficacy in both warranting a tumor reduction by up to 60% of the tumor size and helping the control of seizures. However, the reported rate of side effects is as high as 30% and tumor recurrence is a documented occurrence at the time of mTOR inhibitor discontinuation. Endoscopic tumor removal has been more extensively considered an option due to the acquisition of new tools. Limits are still represented by tumor size (< 3 cm) and broad attachment of the tumor to the basal ganglia. Laser interstitial thermal therapy (LITT) is the more recently considered option. Though promising, only short follow-up is available so far, while data on medium- and long-term results of this treatment are completely lacking to date.

CONCLUSIONS

Surgical treatment remains a mainstay of the management of SEGAs. The indication for an open craniotomic approach should be balanced with an endoscopic tumor removal or LITT according to patient conditions, presence or not of an active hydrocephalus and extension of the attachment of the tumor to the basal ganglia. The mTOR inhibitors do have a definite role both as primary and as adjuvant treatment, but consistent limitations are represented up to now by a not negligible rate of complications and the uncertainties related to the possibility of tumor recurrence once the medical treatment is discontinued.