Surgical treatment of intraventricular tumors associated with tuberous sclerosis

Intraventricular Glioma in Pediatric Patients: A Systematic Review of Demographics, Clinical Characteristics, and Outcomes

OBJECTIVE

We conducted a systematic review on pediatric intraventricular gliomas to survey the patient population, tumor characteristics, management, and outcomes.

METHODS

PubMed, Scopus, Web-of-Science, and Cochrane were searched using PRISMA guidelines to include studies reporting pediatric patients with intraventricular gliomas.

RESULTS

A total of 30 studies with 317 patients were included. Most patients were male (54%), diagnosed at a mean age of 8 years (0.2-19), and frequently exhibited headache (24%), nausea and vomiting (21%), and seizures (15%). Tumors were predominantly located in the fourth (48%) or lateral ventricle (44%). Most tumors were WHO grade 1 (68%). Glioblastomas were rarely reported (2%). Management included surgical resection (97%), radiotherapy (27%), chemotherapy (8%), and cerebrospinal fluid diversion for hydrocephalus (38%). Gross total resection was achieved in 59% of cases. Cranial nerve deficit was the most common postsurgical complication (28%) but most were reported in articles published prior to the year 2000 (89%). Newer cases published during or after the year 2000 exhibited significantly higher rates of gross total resection (78% vs. 39%, P < 0.01), lower rates of recurrence (26% vs. 47%, P < 0.01), longer average overall survival time (42 vs. 21 months, P = 0.02), and a higher proportion of patients alive (83% vs. 70%, P = 0.03) than in older cases.

CONCLUSIONS

Pediatric intraventricular gliomas correlate with parenchymal pediatric gliomas in terms of age at diagnosis and general outcomes. The mainstay of management is complete surgical excision and more recent studies report longer overall survival rates and less cranial nerve complications.

Cortical incisions and transcortical approaches for intra-axial and intraventricular lesions: A scoping review

Background

Transcortical approaches, encompassing various surgical corridors, have been employed to treat an array of intraparenchymal or intraventricular brain pathologies, including tumors, vascular malformations, infections, intracerebral hematomas, and epileptic surgery. Designing cortical incisions relies on the lesion location and characteristics, knowledge of eloquent functional anatomy, and advanced imaging such as tractography. Despite their widespread use in neurosurgery, there is a noticeable lack of systematic studies examining their common lobe access points, associated complications, and prevalent pathologies. This scoping review assesses current evidence to guide the selection of transcortical approaches for treating a variety of intracranial pathologies.

Methods

A scoping review was conducted using the PRISMA-ScR guidelines, searching PubMed, EMBASE, Scopus, and Web of Science. Studies were included if ≥5 patients operated on using transcortical approaches, with reported data on clinical features, treatments, and outcomes. Data analysis and synthesis were performed.

Results

A total of 50 articles encompassing 2604 patients were included in the study. The most common primary pathology was brain tumors (60.6%), particularly gliomas (87.4%). The transcortical-transtemporal approach was the most frequently identified cortical approach (70.48%), and the temporal lobe was the most accessed brain lobe (55.68%). The postoperative course outcomes were reported as good (55.52%), poor (28.38%), and death (14.62%).

Conclusion

Transcortical approaches are crucial techniques for managing a wide range of intracranial lesions, with the transcortical-transtemporal approach being the most common. According to the current literature, the selective choice of cortical incision and surgical corridor based on the lesion's pathology and anatomic-functional location correlates with acceptable functional outcomes.

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.

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.

Identification of TSC1 or TSC2 mutation limited to the tumor in three cases of solitary subependymal giant cell astrocytoma using next-generation sequencing technology

PURPOSE

Subependymal giant-cell astrocytomas (SEGAs) are low grade intraventricular tumors typically found in patients with tuberous sclerosis complex (TSC). The occurrence of SEGA in non TSC patients is very rare and from a genetic point of view these so-called solitary SEGA are thought to result either from somatic mutations in one of the TSC genes (TSC1 or TSC2) limited to the tumor, or be part of a "forme fruste" of TSC with somatic mosaicism. We report on three new cases of solitary SEGA with germline and somatic mutation analysis.

METHODS

We retrospectively analyzed TSC genes in three patients with a solitary SEGA using next-generation sequencing technique.

RESULTS

In the three patients, a somatic mutation of TSC1 or TSC2 was found only in the tumor cells: one patient had a TSC1 heterozygote mutation, involving the natural acceptor splicing site of intron 15 (c.1998-1G > A (p.?). Two patients had a TSC2 mutation located in the canonical splicing donor site of intron 5 (c.599 + 1G > A) in 70% of the alleles in one patient and in exon 9: c.949_955dup7 (p.V319DfxX21) in 25 of the alleles in the second patient. No other TSC mutations were found in patient's blood or tumor and those identified mutations were absent in blood DNA from parents and siblings.

CONCLUSION

We therefore conclude that solitary SEGA can occur with a TSC1 or TSC2 mutation limited to the tumor in patients without TSC.

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

BACKGROUND

Subependymal giant cell astrocytomas (SEGA) are benign tumors characteristic of tuberous sclerosis complex (TSC) that may cause hydrocephalus. Various treatments are nowadays available as mTOR inhibitors or surgery. Surgery is still a valid option especially for symptomatic and larger tumors.

METHODS

From January 1994 to December 2015, 31 TSC patients harboring SEGA underwent surgery at the Department of Neurosurgery of the Meyer Pediatric Hospital, Florence. Indications for surgery were tumor size and location, growth and cystization/hemorrhage, and hydrocephalus. Clinical data, preoperative and postoperative MRI, recurrence rate, further surgical procedures, and related complications were analyzed.

RESULTS

A total of 44 surgeries were performed in 31 TSC patients affected by SEGA, achieving gross total removal (GTR) and subtotal removal (STR), respectively, in 36 and 8 patients. Recurrences occurred in 11 patients; 9 of them underwent further surgical procedures and 2 were treated with mTOR pathway inhibitors. Surgical morbidity and mortality were, respectively, 22.7% and 2.3%. After a mean follow-up of 4.9 years, 90% of patients were tumor-free with good neurological status in 93.3%; twelve (40%) had a ventriculo-peritoneal shunt (VPS) for hydrocephalus.

CONCLUSIONS

The present series confirms that the surgical approach, combined with mTOR inhibitors, is still a valid option for the treatment of SEGAs.

Surgery for subependymal giant cell astrocytomas in children with tuberous sclerosis complex

OBJECTIVE

Subependymal giant cell astrocytomas (SEGAs) are low-grade intraventricular glial tumors that develop in 10-15% of patients with tuberous sclerosis complex; they often cause hydrocephalus and are potentially accessible to a surgical treatment. Our aim is to evaluate morbidity and results after surgery in symptomatic and asymptomatic patients.

METHOD

We present a retrospective series of 18 pediatric patients operated on for SEGA between 2006 and 2016 at our institution. We reviewed surgical indications, preoperative clinical and radiologic data, surgical management, and clinical and radiological follow-up.

RESULTS

Mean age at surgery was 10.7 years. The surgical decision was based on clinical signs of raised intracranial pressure due to hydrocephalus in 8 and on radiological findings without any clinical signs in the other 10 patients (increased in SEGA volume with or without ventricular enlargement). Surgical treatment consisted in a frontal trans-ventricular microsurgical approach in 17 patients and an endoscopic approach in 1. External ventricular drainage was placed in all the patients but 1. Ventriculoperitoneal shunting (VPS) became necessary in 6 patients, all of them presenting with a preoperative active hydrocephalus. Morbidity appeared very low with meningitis occurring in 1 patient. Resection was complete in 15 children with no recurrence during a mean follow-up of 5.25 years and incomplete in 3 requiring a second surgery.

CONCLUSION

Surgery of SEGA represents a very effective treatment with low morbidity and no mortality in the present series. In patients operated before the onset of clinical signs of hydrocephalus, internal VPS could be avoided whereas in others, an additional shunt surgery became necessary. This gives arguments in favor of a regular MRI surveillance in tuberous sclerosis complex patients with SEGA in order to best propose resective surgery once a growth of tumor and/or ventricular size have been confirmed but before raised intracranial pressure occurs.

EFFECTS: an expanded access program of everolimus for patients with subependymal giant cell astrocytoma associated with tuberous sclerosis complex

Background

Everolimus, a mammalian target of rapamycin (mTOR) inhibitor, has been shown to be effective and safe in the treatment of subependymal giant cell astrocytoma (SEGA) associated with tuberous sclerosis complex (TSC). The Everolimus For Fast Expanded aCcess in TSC SEGA (EFFECTS) study was designed to provide everolimus access to patients with SEGA associated with TSC and to mainly assess the safety and also efficacy of everolimus in a real-world setting.

Methods

EFFECTS was a phase 3b, open-label, noncomparative, multicenter, expanded access study. Eligible patients were ≥ 3 years of age, with a definite diagnosis of TSC, and with at least one SEGA lesion identified by MRI or CT scan. Patients received once daily everolimus (dose adjusted to attain a trough level of 5-15 ng/mL). Safety evaluation was the primary objective and included collection of adverse events (AEs) and serious AEs, with their severity and relationship to everolimus. Efficacy evaluation, which was the secondary objective, was based on the best overall response as per medical judgment.

Results

Of the 120 patients enrolled, 100 (83.3 %) completed the study. Median age of patients was 11 years (range, 1-47). Median daily dose of everolimus was 5.82 mg (range, 2.0–11.8). Median duration of exposure was 56.5 weeks (range, 0.3–130). The overall incidence of AEs was 74.2 %. Aphthous stomatitis (18 [15.0 %]), pyrexia (18 [15.0 %]), bronchitis (11 [9.2 %]), and stomatitis (10 [8.3 %]) were the most common AEs reported. Overall, 25 patients had grade 3 AEs; most frequent was stomatitis (4 [3.3 %]). Grade 4 AEs were reported in three (2.5 %) patients. A total of 62 (51.7 %) patients had suspected drug-related AEs, of which 15 (12.5 %) were of grade 3 or 4. In eight (6.7 %) patients, AEs led to drug discontinuation. With regard to efficacy, 81 (67.5 %) patients had a partial response, 35 (29.2 %) had a stable disease, and one (0.8 %) had progressive disease. The response was unknown in three (2.5 %) patients.

Conclusion

This study confirms the acceptable safety profile of everolimus in patients with SEGA associated with TSC in a real-world setting. The results further support the efficacy of everolimus in the treatment of SEGA associated with TSC. (EudraCT: 2010-022583-13)

Subependymal giant cell astrocytoma (SEGA): a case report and review of the literature

Background

Subependymal giant cell astrocytoma is a rare tumor that occurs in the wall of the lateral ventricle and foramen of Monro and, rarely, in the third ventricle. It is one of the intracranial lesions found in tuberous sclerosis complex (which include subependymal nodules, cortical tubers, retinal astrocytoma and subependymal giant cell astrocytoma), but cases without such lesions have also been reported in the literature. It was described for the first time in 1908 by Vogt as part of the typical triad of tuberous sclerosis complex. At the 2012 Washington Consensus Conference, it was decided by the invited expert panel to document the definition of subependymal giant cell astrocytoma as a lesion at the caudothalamic groove with either a size of more than 1 cm in any direction or a subependymal lesion at any location that has shown serial growth on consecutive imaging regardless of size. Most subependymal giant cell astrocytomas will show avid enhancement after contrast administration; however, a growing subependymal lesion even in the absence of enhancement should be considered a subependymal giant cell astrocytoma.

Case presentation

We report a case of subependymal giant cell astrocytoma in a 10-year-old white girl, who had no clinical symptoms of tuberous sclerosis. A computed tomography scan revealed a voluminous mass in her perilateral ventricle. An extemporaneous examination was in favor of a benign ganglioglioma tumor. After fixation in 10 % neutral-buffered formalin, embedding in paraffin and staining with hematoxylin, eosin and safran, the definitive diagnosis was subependymal giant cell astrocytoma.

Conclusions

Subependymal giant cell astrocytoma is a rare tumor of the central nervous system whose diagnosis is based on clinical, radiological, histological and immunohistochemical arguments. For its rarity, we must consider this diagnosis when faced with a mass near the foramen of Monro in the pediatric population even if there are no other features of tuberous sclerosis complex.

Natural History and Current Treatment Options for Subependymal Giant Cell Astrocytoma in Tuberous Sclerosis Complex

Subependymal giant cell astrocytoma (SEGA) is a benign brain tumor associated with tuberous sclerosis complex (TSC). Since there were some discrepancies in SEGA classification, in 2012, a consensus statement defined SEGA as a lesion at the caudothalamic groove with either a size of more than 1cm in any direction or a subependymal lesion at any location that has shown serial growth on consecutive imaging regardless of size. This pointed that the documented tumor growing is an important diagnostic feature. Currently, there are 2 therapeutic options: surgical and medical with mammalian target of rapamycin (mTOR) inhibitors. Neurosurgery should consider a localization and size of the tumor, presence of hydrocephalus and surgeon's experience. Patients who are not qualified for surgery and require therapeutic intervention are subjected to mTOR inhibitors therapy. Everolimus, one of the mTOR inhibitors, has been recently approved in the US and Europe for treatment of patients with TSC and SEGA. Treatment with everolimus results in a rapid initial reduction in tumor volume, followed by a phase of slower reduction or stabilization of residual mass. mTOR inhibitor dose de-escalation strategy seems to be also logical in long-term SEGA treatment to reduce the risk of adverse effects while maintaining the therapeutic effect. However, duration of the treatment and the efficacy of dose reduction are still questionable. Thus, this review covers the various approaches that are currently being made toward improving the outcome of management of SEGA among patients with TSC.

Mammalian Target of Rapamycin Inhibitors and Life-Threatening Conditions in Tuberous Sclerosis Complex

Tuberous sclerosis complex (TSC) is a multisystem disease associated with an overall reduction in life expectancy due to the possible occurrence of different life-threatening conditions. Subjects affected by TSC are, in fact, at risk of hydrocephalus secondary to the growth of subependymal giant cell astrocytomas, or of sudden unexpected death in epilepsy. Other nonneurological life-threatening conditions include abdominal bleeding owing to renal angiomyolipomas rupture, renal insufficiency due to progressive parenchymal destruction by multiple cysts, pulmonary complications due to lymphangioleiomyomatosis, and cardiac failure or arrhythmias secondary to rhabdomyomas. In the last decades, there has been a great progress in understanding the pathophysiology of TSC-related manifestations, which are mainly linked to the hyperactivation of the so-called mammalian target of rapamycin (mTOR) pathway, as a consequence of the mutation in 1 of the 2 genes TSC1 or TSC2. This led to the development of new treatment strategies for this disease. In fact, it is now available as a biologically targeted therapy with everolimus, a selective mTOR inhibitor, which has been licensed in Europe and USA for the treatment of subependymal giant cell astrocytomas and angiomyolipomas in subjects with TSC. This drug also proved to benefit other TSC-related manifestations, including pulmonary lymphangioleiomyomatosis, cardiac rhabdomyomas, and presumably epileptic seizures. mTOR inhibitors are thus proving to be a systemic therapy able to simultaneously address different and potentially life-threatening complications, giving the hope of improving life expectation in individuals with TSC.

Subependymal giant cell astrocytomas in patients with tuberous sclerosis complex: considerations for surgical or pharmacotherapeutic intervention

Tuberous sclerosis complex is a genetic disorder caused by mutations in either the TSC1 or TSC2 gene that can result in the growth of hamartomas in multiple organ systems. Subependymal giant cell astrocytomas are slow-growing brain tumors associated primarily with tuberous sclerosis complex. They are usually located in the ventricles, often near the foramen of Monro, where they can cause an obstruction if they grow too large, leading to increased intracranial pressure. Surgery to remove a tumor has been the mainstay of treatment but can be associated with postoperative morbidity and mortality. Not all tumors and/or patients are suitable for surgery. The recent development of mammalian target of rapamycin inhibitors that target the pathway affected by TSC1/TSC2 mutations offers a novel pharmacotherapeutic option for these patients. We review the timing and use of surgery versus pharmacotherapy for the treatment of subependymal giant cell astrocytoma in patients with tuberous sclerosis complex.

Everolimus (RAD001): first systemic treatment for subependymal giant cell astrocytoma associated with tuberous sclerosis complex

Everolimus (RAD001), a mTOR inhibitor, was initially used as an immunosuppressant in organ transplant patients; however, it also has significant antineoplastic properties. In patients with subependymal giant cell astrocytomas (SEGAs) associated with tuberous sclerosis complex who are not candidates for surgery, single-agent everolimus has demonstrated the ability to significantly reduce SEGA volume with good tolerability. In the Phase III, randomized, placebo-controlled trial, everolimus was associated with a SEGA response rate of 35% compared with 0% in the placebo group. The most common adverse events in clinical trials were stomatitis/mouth ulceration and upper respiratory tract infections, and most adverse events were grade 1 or 2; grade 4 events were rare.

Efficacy and safety of everolimus for subependymal giant cell astrocytomas associated with tuberous sclerosis complex (EXIST-1): a multicentre, randomised, placebo-controlled phase 3 trial

BACKGROUND

Tuberous sclerosis complex is a genetic disorder leading to constitutive activation of mammalian target of rapamycin (mTOR) and growth of benign tumours in several organs. In the brain, growth of subependymal giant cell astrocytomas can cause life-threatening symptoms--eg, hydrocephalus, requiring surgery. In an open-label, phase 1/2 study, the mTOR inhibitor everolimus substantially and significantly reduced the volume of subependymal giant cell astrocytomas. We assessed the efficacy and safety of everolimus in patients with subependymal giant cell astrocytomas associated with tuberous sclerosis complex.

METHODS

In this double-blind, placebo-controlled, phase 3 trial, patients (aged 0-65 years) in 24 centres in Australia, Belgium, Canada, Germany, the UK, Italy, the Netherlands, Poland, Russian Federation, and the USA were randomly assigned, with an interactive internet-response system, in a 2:1 ratio to oral everolimus 4·5 mg/m(2) per day (titrated to achieve blood trough concentrations of 5-15 ng/mL) or placebo. Eligible patients had a definite diagnosis of tuberous sclerosis complex and at least one lesion with a diameter of 1 cm or greater, and either serial growth of a subependymal giant cell astrocytoma, a new lesion of 1 cm or greater, or new or worsening hydrocephalus. The primary endpoint was the proportion of patients with confirmed response--ie, reduction in target volume of 50% or greater relative to baseline in subependymal giant cell astrocytomas. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00789828.

FINDINGS

117 patients were randomly assigned to everolimus (n=78) or placebo (n=39). 27 (35%) patients in the everolimus group had at least 50% reduction in the volume of subependymal giant cell astrocytomas versus none in the placebo group (difference 35%, 95% CI 15-52; one-sided exact Cochran-Mantel-Haenszel test, p<0·0001). Adverse events were mostly grade 1 or 2; no patients discontinued treatment because of adverse events. The most common adverse events were mouth ulceration (25 [32%] in the everolimus group vs two [5%] in the placebo group), stomatitis (24 [31%] vs eight [21%]), convulsion (18 [23%] vs ten [26%]), and pyrexia (17 [22%] vs six [15%]).

INTERPRETATION

These results support the use of everolimus for subependymal giant cell astrocytomas associated with tuberous sclerosis. Additionally, everolimus might represent a disease-modifying treatment for other aspects of tuberous sclerosis.

FUNDING

Novartis Pharmaceuticals.

The outcome of surgical management of subependymal giant cell astrocytoma in tuberous sclerosis complex

OBJECTIVES

The indications for surgery and outcomes of patients who underwent surgical removal of subependymal giant cell astrocytomas (SEGAs) in our institution between 2000 and 2011 were reviewed.

METHODS

We reviewed the clinical details of 16 patients with a diagnosis of Tuberous Sclerosis Complex (TSC) who underwent surgery for SEGA in Bristol since 2000. We collected information on age, sex, epilepsy history and cognitive status. We reviewed the indications for surgery, age at surgery, surgical approach, and the size and location of the lesions. We analysed mortality, completeness of tumour resection, intraoperative blood transfusion, shunt placements, and surgical complications.

RESULTS

13 patients had surgery due to hydrocephalus. Increasing size of SEGA without hydrocephalus was an indication for surgery in two patients, and in one patient, the SEGA was removed because of its size and location at initial scan. 13 patients had complete tumour resection. One patient had tumour recurrence. Hydrocephalus failed to resolve or reoccurred in four patients post operatively necessitating shunt insertion. The surgical approach was transcortical in 14 patients and transcallosal in two. There was zero mortality in this series. There were no reports of cognitive decline or worsening epilepsy following surgery.

CONCLUSION

Surgery is a safe and effective treatment for SEGA. It is the authors' view that surgery remains the most appropriate treatment strategy for SEGAs that are amenable to surgery. More work needs to be undertaken to assess prospectively the neurocognitive impact of surgery, and the relative advantages of different surgical approaches.

Gamma Knife surgery for subependymal giant cell astrocytomas. Clinical article

OBJECT

The authors report their experience of using Gamma Knife surgery (GKS) in patients with subependymal giant cell astrocytoma (SEGA).

METHODS

Over a 20-year period, the authors identified 6 patients with SEGAs who were eligible for GKS. The median patient age was 16.5 years (range 7-55 years). In 4 patients, GKS was used as a primary management therapy. One patient underwent radiosurgery for recurrent tumors after prior resection, and in 1 patient GKS was used as an adjunct after subtotal resection. The median tumor volume at GKS was 2.75 cm(3) (range 0.7-5.9 cm(3)). A median radiation dose of 14 Gy (range 11-20 Gy) was delivered to the tumor margin.

RESULTS

The median follow-up duration was 73 months (range 42-90 months). Overall local tumor control was achieved in 4 tumors (67%) with progression-free periods of 24, 42, 57, and 66 months. Three tumors regressed and one remained unchanged. In 2 patients the tumors progressed, and in 1 of these patients the lesion was managed by repeated GKS with subsequent tumor regression. The other relatively large tumor (5.9 cm(3)) was excised 9 months after GKS. The progression-free period for all GKS-managed tumors varied from 9 to 66 months. There were no cases of hydrocephalus or GKS-related morbidity.

CONCLUSIONS

Gamma Knife surgery may be an additional minimally invasive management option for SEGA in a patient who harbors a small but progressively enlarging tumor when complete resection is not safely achievable. It may also benefit patients with a residual or recurrent tumor that has progressed after surgery.

Management of subependymal giant cell tumors in tuberous sclerosis complex: the neurosurgeon's perspective

BACKGROUND

Tuberous sclerosis complex (TSC), an autosomal dominant genetic disorder, can lead to the development of hamartomas in various organs, including the heart, lungs, kidneys, skin and brain. The management of subependymal giant cell tumors (SGCTs) is still controversial, and peri- and/or intraventricular neoplasms may lead to life-threatening hydrocephalus. In the last years, many progresses have been made in research into the tumorigenesis and behaviors of SGCTs. This review aims to clarify the specific role of neurosurgeons in the multidisciplinary management of SGCTs in children with TSC.

DATA SOURCES

Based on the recent scientific literature and personal experience, we reviewed the up-to-date data and discussed the trends in the management of SGCTs in children with TSC. The data were collected after a bibliography made using PubMed/Medline with these terms: subependymal, subependymal giant cell astrocytoma, subependymal giant cell tumor, and tuberous sclerosis complex.

RESULTS

SGCTs are shown to be generated from a glioneuronal lineage, but their filiation with subependymal nodules (SENs) is still under debate. While SENs may develop anywhere in the ventricular walls, SGCTs arise almost exclusively around the Monro foramina. In children with TSC, precise clinical and/or imaging criteria are mandatory to differentiate SENs that are always asymptomatic and riskless from SGCTs that have the potential to grow and therefore to obstruct cerebrospinal fluid pathways leading to hydrocephalus.

CONCLUSIONS

An earlier diagnosis of SGCT in neurologically asymptomatic children with TSC may allow a precocious surgical removal of the tumor before the installation of increased intracranial pressure signs, an attitude that is being progressively adopted to lessen the morbimortality rate.

Extraventricular subependymal giant cell tumor in a child with tuberous sclerosis complex

Subependymal giant cell tumors (SGCTs) are observed in 5-20% of patients with tuberous sclerosis complex (TSC) but account for approximately 25% of neurological morbidity. The authors report the case of a 7-year-old girl with TSC and multiple cortical tubers who presented with worsening seizures in the context of the rapid growth of a cystic, calcified, extraventricular SGCT in the right frontal lobe, initially thought to represent a cortical tuber. The tumor and surrounding tubers were excised, and clinical seizures resolved. This is the first report of an extraventricular SGCT in a child with TSC outside the neonatal period.

[Phacomatosis and genetically determined tumors: the transition from childhood to adulthood]

Phacomatoses, or neurocutaneous disorders, are a group of congenital and hereditary diseases characterized by developmental lesions of the neuroectoderm, leading to pathologies affecting the skin and the central nervous system. There is a wide range of pathologies affecting individuals at different moments of life. The genetics is variable: while neurofibromatosis 1 and 2, tuberous sclerosis and von Hippel-Lindau disease are all inherited as autosomal dominant traits, Sturge-Weber syndrome is sporadic. Other neurocutaneous disorders can be inherited as autosomal recessive traits (i.e., ataxia-telangiectasia), X-linked (i.e., incontinentia pigmenti) or explained by mosaicism (i.e., hypomelanosis of Ito, McCune-Albright syndrome). In this review, we discuss the major types of neurocutaneous disorders most frequently encountered by the neurosurgeon and followed beyond childhood. They include neurofibromatosis types 1 and 2, tuberous sclerosis, Sturge-Weber syndrome and von Hippel-Lindau disease. In each case, a review of the literature, including diagnosis, genetics and treatment will be presented. The lifespan of the disease with the implications for neurosurgeons will be emphasized. A review of cases, including both pediatric and adult patients, seen in neurosurgical practices in the Lille, France and Lausanne, Switzerland hospitals between 1961 and 2007 is presented to illustrate the pathologies seen in different age-groups. Because the genes mutated in most phacomatoses are involved in development and are activated following a timed schedule, the phenotype of these diseases evolves with age. The implication of the neurosurgeon varies depending on the patient's age and pathology. While neurosurgeons tend to see pediatric patients affected with neurofibromatosis type 1, tuberous sclerosis and Sturge-Weber syndrome, there will be a majority of adult patients with von Hippel-Lindau disease or neurofibromatosis type 2.

Subependymal giant cell astrocytoma (SEGA): Is it an astrocytoma? Morphological, immunohistochemical and ultrastructural study

Subependymal giant-cell astrocytoma (SEGA) is a rare intra-ventricular low-grade tumor which frequently occurs as a manifestation of tuberous sclerosis complex. The histogenesis of SEGA is controversial and its astrocytic nature has been doubted. First studies suggested the astrocytic nature of SEGA while several recent reports demonstrate its glio-neuronal nature. In spite of this, in the recently revised WHO classification of the CNS tumors, SEGA has been still included in the group of astrocytomas. We studied nine tuberous sclerosis complex-associated SEGAs. Patients were 1-18 years old. Eight patients (89%) had a solitary lesion located in the lateral ventricle close to of the head of the caudate nucleus, the remaining patient (11%) had two tumors, one located close to the head of the left caudate nucleus and the other in the central part of the right lateral ventricle. Histologically, tumors were composed of three types of cells: spindle, gemistocytic and ganglion-like. Four tumors (44%) had a prominent vascularization and three (33%) showed an angiocentric pattern. Calcifications were observed in six cases (66%). By immunohistochemistry, the majority of the tumors were GFAP- (9; 100%), neurofilament- (8, 89%), neuron-specific enolase- (9, 100%), and synaptophysin- (8; 89%) positive. Ultrastructural studies were performed on four cases. In all four there were glial cell processes filled with intermediate filaments. In one case dense core putative neurosecretory granules were appreciable. Our results emphasize the glio-neuronal nature of SEGA. We suggest moving it into the group of mixed glio-neuronal tumors under the denomination of subependymal giant cell tumor.

Subependymal giant-cell astrocytomas in pediatric tuberous sclerosis disease: when should we operate?

OBJECTIVE

A small percentage of tuberous sclerosis patients will develop a subependymal giant-cell astrocytoma. Given the morbidity and mortality when such a lesion is left undiagnosed, successive follow-up imaging in pediatric patients has been recommended. Surgical removal of the lesion has become the procedure of choice; however, the timing of this surgery is still a controversial subject. By analyzing our own series of data, as well as other published series, we have attempted to reach a consensus on the benefits of early versus late surgery.

METHODS

We retrospectively reviewed 19 patients treated surgically for intraventricular tumors in Foch Hospital and at the Fondation Adolphe de Rothschild in Paris, France, and we analyzed published pediatric reports from 1980 to 2006.

RESULTS

The results from our own population, as well as from other published pediatric series (15 series), indicate that subependymal giant-cell astrocytomas have a good prognosis when a macroscopically total resection has been performed. In our series, residual lesions tended to enlarge, but residual tumors remaining stable have been reported. Careful follow-up examination should be undertaken because late recurrences do occur. Larger or symptomatic lesions tend to have a higher morbidity.

CONCLUSION

We think that any lesion fulfilling the criteria for a subependymal giant-cell astrocytoma as previously described in the literature (lesion around the foramen of Monro, greater than 5 mm, with incomplete calcifications) should be removed as soon as clear evidence of growth has been confirmed.

Giant Cells: Contradiction to Two-Hit Model of Tuber Formation?

Tuberous sclerosis (TSC) is an autosomal dominant disease characterized by the formation of hamartomatous lesions in many organs, including brain, heart or kidneys. It has been found that TSC is caused by the mutation in one of the two tumor suppressor genes: TSC1 or TSC2, encoding hamartin and tuberin, respectively. According to Knudson's two-hit model of tumorigenesis, second-hit mutation and resulting loss of heterozygosity (LOH) of a tumor suppressor gene is necessary for tumor formation. In fact, LOH is commonly found in several types of hamartomas formed in the process of tuberous sclerosis, but, interestingly, not in brain lesions, containing characteristic giant cells. In this paper, we review literature covering origination of giant cells and present several hypotheses explaining why in spite of the presence of hamartin and tuberin, brain lesions form in TSC patients.

Giant Cells: Contradiction to Two-Hit Model of Tuber Formation?

1. Tuberous sclerosis (TSC) is an autosomal dominant disease characterized by the formation of hamartomatous lesions in many organs, including brain, heart or kidneys. It has been found that TSC is caused by the mutation in one of two tumor suppressor genes: TSC1 or TSC2, encoding hamartin and tuberin, respectively. 2. According to Knudson's two-hit model of tumorigenesis, second-hit mutation and resulting loss of heterozygosity (LOH) of a tumor suppressor gene is necessary for tumor formation. In fact, LOH is commonly found in several types of hamartomas formed in the process of tuberous sclerosis, but, interestingly, not in brain lesions, containing characteristic giant cells. 3. In the present paper we review literature covering origination of giant cells and present several hypotheses explaining why in spite of the presence of hamartin and tuberin, brain lesions form in TSC patients.

Subependymal giant cell astrocytoma: a report of five cases

Five cases of intraventricular subependymal giant cell astrocytomas (SEGCA) were retrospectively reviewed. Records and detailed work-up of all five cases were well maintained in view of rare occurrence of these tumors. The five patients were males aged 10, 12 (2 cases), 14 and 18 years. The 18-year-old aged male had no stigmata of tuberous sclerosis (TSC) on examination, while the rest presented with features of TSC, intraventricular tumors and hydrocephalus. None of the five cases had renal tumors and did not reveal cardiac tumors. Skin manifestations like shagreen patches were present in two, facial angiofibromas in three, periungal fibromas in two, hypopigmented macules in two and ash-leaf spot in two patients. Fundoscopic examination revealed retinal astrocytomas in two cases only. Two of the five children did not have mental compromise. A child who started throwing seizures early (at 5 months of age) had severe mental retardation. Although SEGCA is a less vascular tumor, one tumor bled profusely intraoperatively; it was excised rapidly via the transcortical route to salvage the life of the child, though he was planned for the transcallosal route like the other cases. The tumor of another child was also very vascular. Four children survived surgery and required no shunt CSF diversion, while one died of severe ventriculitis and septicemia 3 weeks after surgery.

Neurosurgical treatment of brain tumors in children

Primary brain tumors are the most common solid neoplasms of childhood. The diagnosis of brain tumors in the general pediatric population remains challenging. Nevertheless, it is clear that refinements in imaging, surgical technique, and adjunctive therapies have led to longer survival and an improving quality of life in children with brain tumors.

Subependymal giant cell astrocytoma in children with tuberous sclerosis

METHODS

Out of 105 patients with tuberous sclerosis (TS) admitted to the Hospital Nacional de Pediatría "Juan P. Garrahan" (Buenos Aires, Argentina), we surgically treated 17 children between January 1988 and December 2000. Two patients were operated on because of epilepsy and 15 patients because of an intraventricular tumor (subependymal giant cell astrocytoma [SGCA]). In this report we focus on tumors. Twelve of the 15 patients presented with hydrocephalus but none of them had a preoperative shunt. All tumors were surgically resected using frontal transventricular or transcallosal routes. Total removal was achieved in 12 out of 15 and subtotal removal in 3 out of 15 patients (resection of 70-95%).

RESULTS

Exeresis of the tumor was not accompanied by significant morbidity and there was no perioperative mortality. Seizures and mental retardation did not improve after tumor resection. It was necessary to insert a postoperative shunt a long time after surgery in only one patient. There were no recurrences of SGCA that were totally removed after a mean follow-up of 51.7 months.

CONCLUSIONS

We encourage surgery as soon as a lesion is diagnosed as a tumor. The "transformation" of subependymal nodules (SEN) into tumors (SGCA) may be considered controversial.

Neurocutaneous disorders

"Neurocutaneous disorders" is a catch-all phrase that includes all disorders involving both the nervous systems and the skin. These may range from disorders in which cutaneous findings are essential to diagnosis to those with less significant involvement of the skin. Because of the variety of disorders that involve the skin and the nervous system, this article reviews a few of the more essential diagnoses, and those with recent advancements in diagnosis and management. Many of these diseases are single gene disorders, for which the genes have been discovered in the past few years. The article is divided into sections, highlighting disorders transmitted by different inheritance pattern.

Tumours around the foramen of Monro: clinical and neuroimaging features and their differential diagnosis

The clinical and neuroimaging features of 20 patients with lateral ventricular tumours located around the foramen of Monro were reviewed retrospectively with special emphasis on the differential diagnoses. Histologic types were: eight neurocytomas, four subependymal giant cell astrocytomas (SGCAs), three subependymomas, two fibrillary astrocytomas, and one each of pilocytic astrocytoma, malignant astrocytoma and malignant teratoma. The mean age of the patients with neurocytoma was 29.6 years, with SGCA 13.3 years and with subependymoma 55.3 years. All tumours appeared nodular in shape, and on computed tomography (CT) neurocytomas were either isodense or highdense with the brain, while all subependymomas and SGCAs were lowdense. Calcification was observed in two SGCAs, and one neurocytoma. Five neurocytomas and all four SGCAs showed mild to moderate contrast enhancement, while all three subependymomas showed either no, or scarce, enhancement. Magnetic resonance imaging (MRI) studies were available in 10 patients, with the signal characteristics of four neurocytomas and three SGCAs being nonspecific, while two subependymomas were both hypointense on T1-weighted images and hyperintense on T2-weighted images. Thus important features for differential diagnosis included age of the patient and density on precontrast CT. In this series, either an extensive excision of the tumour or a partial removal, thus relieving the obstruction of the foramina of Monro, usually provided long term survival, with 18 patients surviving a mean of 10.8 years.

Pediatric supratentorial intraventricular tumors

A variety of mass lesions can arise within or in proximity to the ventricular system in children. These lesions are relatively uncommon, and they present a unique diagnostic and surgical challenge. The differential diagnosis is determined by tumor location in the ventricular system, clinical presentation, age of the patient, and the imaging characteristics of the lesion. In this report the authors provide an introduction to and an overview of the most common pediatric supratentorial intraventricular tumors. The typical radiographic features of each tumor and location preference within the ventricular system are reviewed. Management and treatment considerations are discussed. Examination of tissue samples to obtain diagnosis is usually required for accurate treatment planning, and resection without adjuvant therapies is often curative. The critical management decision frequently involves determining which lesions are appropriate for surgical therapy. Care ful preoperative neuroimaging is extremely useful in planning surgery. Knowledge of the typical imaging characteristics of these tumors can help to determine the diagnosis with relative certainty when a tissue sample has not been obtained, because a small subset of these lesions can be managed expectantly.

Transcortical surgery for lateral ventricular tumors

Object

Tumors of the lateral ventricle can be removed via two major approaches: the transcallosal or the transcortical route. The purpose of this study is to discuss the techniques and outcomes in transcortical surgery of tumors located in the lateral ventricle.

Methods

An experience with 29 consecutive lateral ventricular tumors resected via the transcortical route, over a 5-year period, is presented. The risks, complications, and outcomes of this surgical series, as well as those reported in the literature, are discussed. Surgical approaches to all five regions of the lateral ventricle are described. Neuropsychological, functional, and neurological outcomes are evaluated.

Conclusions

The transcortical technique makes it possible to resect lesions in each of the five regions of the lateral ventricle. It provides superior microsurgical working space and flexibility for maneuvering within the lateral ventricle. The key to a successful transcortical approach is an understanding of the functional anatomy of eloquent cortex to be broached, the location of the lesion, and its vascular supply. A clear understanding of the advantages and limitations of the transcortical approach makes performing this procedure for resection of large lesions in the ventricle both safe and effective. The majority of the patients in this series (86%) had a good outcome, returning to baseline functional status and suffering minimal morbidity. In the microsurgical era, transcortical surgery–related postoperative morbidity and outcome are dependent more on tumor histological type and site of origin than on approach.

Subependymal giant cell astrocytoma: clinical and neuroimaging features of four cases

The clinical history, neuroimaging features, treatments, and outcome of 4 patients with histologically verified subependymal giant cell astrocytomas (SEGA) were retrospectively reviewed. The average age at the time of surgery was 13.3 years. Headache related to raised intracranial pressure was the first and only sign in 2 patients, with the remaining 2 being admitted because of sequential neuroimaging studies over several years revealing the growth of 'subependymal nodules' into intraventricular tumours. In each case the tumour was in the region of Monro's foramen and was associated with ventricular dilatation. On computed tomography (CT), multiple subependymal nodules were found in 3 patients, and these well circumscribed isodense SEGAs were markedly enhanced by contrast medium. On magnetic resonance imaging (MRI), which was obtained in 3 patients, 2 SEGAs were isointense with the cerebral cortex and one with the white matter on T1-weighted images, and on T2-weighted images, 2 were isointense with the cortex and one with the white matter. At surgery the tumours appeared to originate from the inferolateral wall of the lateral ventricle in the region of the head of the caudate nuclei. Total macroscopic removal was achieved in 3 patients, and subtotal removal in one patient. Follow up ranged from 4.6 to 13.2 years, and all patients have exhibited similar physical and mental conditions to preoperative. So far there has been no evidence of any recurrences. The diagnosis and the surgical indications for SEGA are discussed, with periodic monitoring with neuroimaging studies being recommended even for asymptomatic patients with 'subependymal nodules'.

Usefulness of diagnostic criteria of tuberous sclerosis complex in pediatric patients

The Tuberous Sclerosis Complex 1998 Consensus Conference clinical criteria represent an important advance in the diagnosis of tuberous sclerosis complex. Since many findings regarded as highly specific for tuberous sclerosis complex are not apparent until late childhood or adulthood, refinements by age may prove of value. We have stratified 106 children into five age groups (0 to 2 years of age, above 2 to 5 years, above 5 to 9 years, above 9 to 14 years, and above 14 to 18 years). Physicians should be alerted as to the frequency of the criteria in different stages of children.

Skin lesions in children with tuberous sclerosis complex: their prevalence, natural course, and diagnostic significance

BACKGROUND

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by widespread cutaneous and visceral hamartomas.

METHODS

The prevalence of cutaneous lesions in 106 children with TSC (47 boys and 59 girls) aged 1 month-18 years was evaluated from 1984 to 1995. Assessing the diagnostic usefulness of each National Tuberous Sclerosis Association skin criterion was an aim of this study.

RESULTS

Hypopigmented macules were the most frequent finding, seen in 103 of 106 children (97.2%). In 66 children they were evident at birth, and in 20 others their presentation was delayed until the first months of age. Facial angiofibromas were seen next most often (79 of 103, 74.5%), followed by a shagreen patch in 51 of 103 (48.1%), "cafe-au-lait" macules in 30 of 103 (28.3%), molluscum fibrosum pendulum (24 of 103, 22.6%), a forehead fibrous plaque (20 of 103, 18.9%), periungual fibromas (16 of 103, 15.1%) and "confetti-like" macules (3 of 103, 2.8%). The hypomelanotic macules were seen within the first 2 years of life in 95 children, as were café-au-lait spots in 24, facial angiofibromas in eight, shagreen patches in six, and forehead fibrous plaques in six, whereas molluscum pendulum and periungual fibromas were not evident. Seizures were seen in 102 of 106 children (98%), with 80 (75%) occurring during the first year of life.

CONCLUSIONS

Hypomelanotic macules were the overwhelmingly most common early finding in TSC. Infants with seizures or other possible stigmata of TSC should be carefully evaluated for these hypomelanotic macules, as well as for other associated findings.

Early diagnosis of subependymal giant cell astrocytoma in patients with tuberous sclerosis

We present 19 patients with tuberous sclerosis complex and subependymal giant cell astrocytoma. The mean age at the time of tumor diagnosis was 9.4 years (range, 1.5 to 21 years). Computed cranial tomography (CT) or cranial magnetic resonance imaging (MRI) identified the lesion which was resected in all cases. Seven patients had hydrocephalus and there was an interval increase in the tumor size or a large tumor without hydrocephalus in 12 patients. Surgical criteria included: (1) presence of hydrocephalus; (2) interval increase in tumor size; (3) new focal neurologic deficit attributable to the tumor; and/or (4) symptoms of increased intracranial pressure. Eight patients were identified through a surveillance program involving annual computed cranial tomography. All of these eight patients had their tumor removed prior to the development of symptoms, none had neurologic deficits which persisted after surgery, and none has so far developed recurrent subependymal giant cell astrocytoma. In contrast, of the 11 patients from the non-surveillance group 7 were symptomatic at tumor diagnosis, 1 had a complicated postoperative course, 2 developed recurrent giant cell astrocytoma, and 1 had an extensive lesion that could not be completely excised. Periodic cranial imaging may help to identify subependymal giant cell astrocytomas in tuberous sclerosis patients before they become symptomatic. Earlier diagnosis and treatment could reduce surgical morbidity and the risk of tumor recurrence.