Intraventricular Tumors: Surgical Considerations in Lateral and Third Ventricular Tumors

Management of lateral and third ventricular tumors has been a challenge for neurosurgeons. Advances in imaging and pathology have helped in a better understanding of the treatment options. Technical refinement of microsurgical technique and addition of endoscopy has enabled more radical excision of tumors, when indicated, and added more safety.A proper understanding of the pathology at various ages and treatment options is continuously evolving. Many pediatric tumors are amenable to conservative surgical methods with effective complementary treatments. However, radical surgery is required in many adults as the main treatment and for many benign tumors. Various intraventricular lesions encountered and their surgical management is reviewed here for their efficacy, safety, and outcome, encompassing changes in our practice over the last 20 years.

Neuroendoscopy: intraventricular and skull base tumor resection in children

During the last 30 years, the neurosurgeons have witnessed a revolution in the practice of interventricular surgery. The advent of neuroendoscopy at the end of the 1980s has allowed a minimally invasive management of a very large series of pathologies in pediatric neurosurgery ranging from hydrocephalus to arachnoid cyst to intraventricular tumors. The progresses in the management of hydrocephalus, intracranial cyst, and the fluid filled collection nevertheless has been more rapid and radical due to the simpler equipment that is necessary to perform this kind of surgery. The intraventricular tumors instead have been addressed in a slower way, and for many years, the only endoscopic procedure that was allowed on interventricular tumors was a biopsy associated with the management of hydrocephalus. Only very small tumors have been considered operable for complete removal during many years due to the limitations of the neuroendoscopic equipment and to the small calibers of the working channel. More recently, the advent of new devices and new surgical techniques are offering new perspectives on the possibility of intraventricular tumor surgery in children. In this review, we describe the historical perspective of the learning curve of intraventricular tumor surgery under neuroendoscopic control and try to offer a view of the future perspective in the removal of larger intraventricular tumors, analyzing the main indications for intraventricular endoscopic tumor surgery. We offer as well an historical perspective of the evolution of skull base surgery and endonasal transsphenoidal approach for skull-based tumors in children. This kind of surgery that has acquired widespread acceptance for many pathologies in adult age has diffused more slowly in pediatric neurosurgery due to the anatomical limitation observed in these age range. Also in this field, the slow evolution of the technique and of the technology available to neurosurgeons has allowed a very significant expansion of indication for the minimally invasive removal of skull base tumors in children.

Neuroendoscopy in the management of pineal region tumours in children

INTRODUCTION

Pineal region tumours (PRTs) are more common in children and represent a wide variety of lesions. The practise of a radiation test dose is obsolete and a biochemical/histological diagnosis is recommended before further therapy. Many patients present with hydrocephalus. Advances in neuroendoscopic techniques have allowed safe and effective management of this obstructive hydrocephalus with an opportunity to sample cerebrospinal fluid (CSF) and obtain tissue for histopathology. Definitive surgery is required in less than a third. Endoscopic visualisation and assistance is increasingly used for radical resection, where indicated.

METHODOLOGY

Our experience of endoscopic surgery for paediatric PRTs from 2002 to 2021 is presented. All patients underwent MRI with contrast. Serum tumour markers were checked. If negative, endoscopic biopsy and endoscopic third ventriculostomy (ETV) were performed; and CSF collected for tumour markers and abnormal cells. For radical surgery, endoscope-assisted microsurgery procedures were performed to minimise retraction, visualise the extent of resection and confirm haemostasis.

RESULTS

M:F ratio was 2:1. The median age of presentation was 11 years. Raised ICP (88.88%) was the commonest mode of presentation. Nineteen patients had pineal tumours, one had a suprasellar and pineal tumour, one had disseminated disease, while six had tectal tumours. The ETB diagnosis rate was 95.45%, accuracy rate was 83.3% and ETV success rate was 86.96%.

CONCLUSION

Neuroendoscopy has revolutionised the management of paediatric PRTs. It is a safe and effective procedure with good diagnostic yield and allows successful concurrent CSF diversion, thereby avoiding major surgeries and shunt implantation. It is also helpful in radical resection of lesions, where indicated.

Cystic Cerebral Cavernous Malformations: Report of Five Cases and a Review of Literature

Introduction  Cerebral cavernous malformations (CCMs) account for about 5 to 13% of intracranial vascular malformations. Cystic cerebral cavernous malformations (cCCMs) are a rare morphological variant and can cause diagnostic and therapeutic dilemmas. We describe our five such cases and review the existing literature on this entity. Methods  A search of the PubMed database for cCCMs was done, and all articles in English emphasizing the reporting of cCCMs were selected. A total of 42 publications describing 52 cases of cCCMs were selected for analysis. Epidemiological data, clinical presentation, imaging features, the extent of resection, and outcome were analyzed. Radiation-induced cCCMs were excluded. We have also described five of our cases of cCCMs and reported our experience. Results  The median age at presentation was 29.5 years. Twenty-nine patients had supratentorial lesions, 21 had infratentorial lesions, and 2 had lesions in both compartments. Among our four patients, three had infratentorial lesions, whereas one had a supratentorial lesion. Multiple lesions were seen in four patients. A majority (39) had symptoms of mass effect (75%), and 34 (65.38%) had raised intracranial pressure (ICP), whereas only 11 (21.15%) had seizures. Among our four operated patients, all of them had symptoms of mass effect, and two of them also had features of raised ICP. The extent of resection was gross total in 36 (69.23%), subtotal in 2 (3.85%), and not reported in 14 (26.93%). All four of our operated patients underwent gross total resection, but two of them underwent a second surgery. Of the 48 patients in whom the surgical outcome was reported, 38 improved (73.08%). One showed a transient worsening followed by improvement, one developed a worsening of the pre-existing focal neurological deficit (FND), two developed a new FND, and 5 had no improvement in their FNDs. Death occurred in one patient. All four of our operated patients improved after surgery, although three of them showed a transient worsening of FNDs. One patient is under observation. Conclusion  cCCMs are rare morphological variants and can cause considerable diagnostic and therapeutic dilemmas. They should be considered in the differential diagnosis of any atypical cystic intracranial mass lesion. Complete excision is curative, and the outcome is generally favorable; although transient deficits may be seen.

A comparison of Adult and Pediatric Hydrocephalus

Hydrocephalus is a common clinical problem encountered in neurosurgical practice. With greater subspecialisation, pediatric neurosurgery has emerged as a special discipline in several countries. However, in the developing world, which inhabits a large pediatric population, a limited number of neurosurgeons manage all types of hydrocephalus across all ages. There are some essential differences in pediatric and adult hydrocephalus. The spectrum of hydrocephalus of dysgenetic origin in a neonate and that of normal pressure hydrocephalus of the old age has a completely different strategy of management. Endoscopic third ventriculostomy outcomes are known to be closely associated with age at presentation and surgery. Efficacy of alternative pathways of CSF absorption also differs according to age. Managing this disease in various age groups is challenging because of these differences in etiopathology, tempo of the disease, modalities of investigations and various treatment protocols as well as prognosis.

Intraventricular Craniopharyngiomas-Overcoming Their Relative Inaccessibility: Institutional Experience With a Review of Literature

Introduction: Craniopharyngiomas constitute 2-4% of intracranial neoplasms. Intraventricular craniopharyngiomas (IVCrs) are the rarely encountered varieties of these lesions. Objective: The objective of the study was to study the special features in clinical presentation, imaging, management, and surgical outcome of IVCrs. Materials and Methods: This retrospective analysis included the combined experience from two tertiary care institutions. Medical records of histopathologically proven cases of IVCrs from January 1994 to June 2021 were assessed, and images were analyzed based on the criteria by Migliore et al. for inclusion of solely intraventricular lesion with the third ventricular ependyma demarcating it from the suprasellar cistern. Results: Among the 25 patients included (mean age: 35.4 years), the most common presentation included headache (n = 21, 84%), vomiting and other features of raised ICP (n = 18, 72%), visual complaints (n = 12, 48%), and endocrinopathies (n = 11, 44%). Fifteen had predominantly cystic tumors, two were purely solid, and eight were of mixed consistency. Primary open microsurgical procedures were performed in 18 (72%) patients, of which four (16%) were endoscope-assisted. Seven (28%) underwent a purely endoscopic procedure. One underwent a staged surgery with endoscopic cyst fenestration and intracystic interferon (IFN)-alpha therapy, followed by microsurgical excision. Complete excision was achieved in 10 patients, near-total in nine, and partial excision in six. Four patients underwent a ventriculoperitoneal shunt (one before the definitive procedure). At a median follow-up of 36 months (range:11-147 months), five patients developed a recurrence, and one had a stable small residue. This patient and two others with small cystic recurrences were observed. One patient was managed with radiotherapy alone. Another underwent re-surgery after a trial of radiotherapy, and the last patient developed a local recurrence, which was managed with radiotherapy; he then later developed an intraparenchymal recurrence, which was operated. Conclusion: Purely IVCrs present with raised intracranial pressure, and visual disturbances are less common. Their deep-seated location and limited surgical field-of-view makes minimally invasive endoscopic-assisted surgery most suitable for their excision. The thin-walled cystic lesions may be occasionally adherent to the ependymal wall in close vicinity to the thalamus-hypothalamus complex, making complete excision difficult. Their responsiveness to radiotherapy, often leads to a gratifying long-term outcome.

Paediatric giant cavernomas: report of three cases with a review of the literature

INTRODUCTION

Cavernous angiomas of the brain (CCM) are being increasingly diagnosed, especially in the paediatric age group. Though classic presentations with haemorrhage or seizures are well recognised, presentation as a large lesion with mass effect is rare and creates difficulty in diagnosis as well as management.

METHODS

Our cases of paediatric giant CCMs that presented as a 'mass lesion' are reported here, and the PubMed database for giant CCMs in the paediatric population is reviewed. All articles where the size of the lesion was reported to be > 4 cm were selected for analysis to study the varying modes of presentation, treatment, and outcome; to gain a proper perspective on this distinct entity of 'giant CCMs'.

RESULTS

Analysis of a total of 53 cases (inclusive of our 3 cases) reported so far showed slight male preponderance (58.49%). The largest reported lesion was 14 cm in largest diameter. Most of the lesions (83.02%) occurred in the supratentorial region. In the infratentorial region, paediatric giant CCMs were more commonly seen in the cerebellum than in the brainstem. Seizures were observed in 47.17% at presentation. Features of mass effect were the mode of presentation in all our cases, and literature analysis has shown raised intracranial pressure in 37.74% (20 patients) and focal neurological deficit in 33.96% (18 patients) at presentation. Macrocephaly was seen in younger children up to the age of 7 years (16.98% or 9 patients). Gross total resection was carried out (with a good outcome) in all our cases and in 36 of the other 49 analysed patients who were operated on.

DISCUSSION

About one-fourth of CCMs occur in paediatric patients. Giant CCMs are rare but can present in children even in the immediate post-natal period. Features of a mass lesion such as raised intracranial pressure, macrocephaly, and focal neurological deficit are much more common than their smaller counterparts. Their appearance on imaging also often causes diagnostic dilemmas with other intracranial mass lesions. Timely surgery with standard microsurgical principles leads to a favourable outcome in the majority.

CONCLUSION

Giant CCMs, though rare, often present as a diagnostic challenge. Presentation with mass effect is common, and complete microsurgical excision remains the mainstay of treatment. Though transient neurological deficits may be encountered with this strategy, the long-term outcome remains favourable.

The reconstruction of skull base defects in infants using pedicled nasoseptal flap-a review of four cases

INTRODUCTION

Benign lesions of the skull base are common in the paediatric population, and are usually congenital in aetiology. Majority of these lesions are treated transcranially exposing the patients to a number of risks. Although endoscopic endonasal surgery (EES) helps avoid many of these potential morbidities, CSF leak with its attendant complication remains a big concern. This study reports the use of the Hadad flap in the reconstruction of skull base defects in infants to prevent this problem. The study was conducted on four infants with a mean age of 7 months, who underwent repairs for CSF leaks associated with congenital lesions like meningocele or meningoencephalocele, using the Hadad flap. Of the four patients, three cases were revision cases and one was primary where the patients presented with complaints such as nasal obstruction and watery nasal discharge. Post surgery, the infants were monitored for a mean period of 23 months and no major complications or recurrent CSF drainage were observed. Minor complications that were observed include vestibulitis and crusting in the nose. The utility of the Hadad flap in the reconstruction of skull base defects in the paediatric age group has been controversial while its utility in infants has not been studied in literature so far. We report here in our series four infant patients in whom we believe that the nasal septum and the skull base will develop proportionally to each other, hence lowering the chances of a short flap and eliminating the occurrence of future complications.

CONCLUSION

The nasoseptal flap is an effective and safe technique for reconstructing skull base defects in infancy. It can be concluded that this technique does not have any potential effect on septal or craniofacial growth as the flap is harvested only on one side with normal mucosal cover on the other side. There is no posterior septectomy or any form of bony or cartilaginous resection that is performed, hence avoiding any effects on bony growth. No studies have been published in literature so far and to the best of our knowledge, this is the first report describing the efficacy of the nasoseptal flap in infants.

Symptomatic Granuloma Secondary to Embolic Agent: A Case Report

Onyx is a liquid embolic agent presently gaining wide acceptance for embolisation of multiple vascular cranial pathologies like Arteriovenous Malformation (AVM) and Arteriovenous Fistula (AVF). Onyx stays in the nidus of vascular pathology and initiates inflammatory response leading to thrombosis and subsequently resulting in occlusion of vascular nidus. However, if onyx spills into the surrounding brain tissue, reaction occurs in the form of foreign body inflammatory reaction. This is one of the very few cases in literature whereby embolisation of AVM with onyx lead to granuloma formation which needed surgical excision. It presented with limb weakness and seizure episodes.

Endoscopic Excision of Symptomatic Simple Bone Cyst at Skull Base

Seizure is a classical feature of intra axial brain parenchymal lesion. Simple bone cyst is an unusual bony pathology at skull base presenting with unexpected symptoms of complex partial seizures. Skull base neuro-endoscopy has managed such lesions more effectively with reduced post-operative morbidity as compared to transcranial approach. This case report discusses a 20-year-old male who presented with 3 episodes of seizure over a time period of 10 months. MRI brain revealed T1 hypo and T2 hyper intense cystic lesion in middle cranial fossa with no enhancement on contrast administration. CT scan showed cystic lesion involving greater wing and pterygoid plate of sphenoid on left side. CT cisternographic evaluation showed CSF outpouching in the sphenoid air sinus. Excision of the cystic lesion was carried out through endoscopic transmaxillary transpterygoid approach. Histopathological examination showed the lesion to be a simple bone cyst.

Transformation of a meningioma with atypical imaging

Meningiomas are benign tumors of the central nervous system. They have long term curability if they are excised completely. If not, they can recur after a prolonged period and can lead to increased morbidity during re-surgery. Recurrence is rarely associated with invasiveness. Usually de-differentiation in case of meningiomas is uncommon without any predisposing factors including different genetic mutations or radiation to the involved region. We report a case of a 38-year-old female who was operated for a benign para-sagittal meningioma 8 years back and subsequently developed an invasive recurrence off late. Also this time, the imaging morphology was slightly different for a meningioma and gross as well as microscopic findings were very atypical. Awareness for such cases must be there while dealing with recurrent meningiomas as invasiveness may not always be associated with adverse predisposing factors like radiation. As invasiveness is always a histopathological diagnosis, picking up such features on imaging is a daunting task and if done, can help neurosurgeons prognosticate such invasive recurrences in a better fashion.

Real-time PCR assay based on the differential expression of microRNAs and protein-coding genes for molecular classification of formalin-fixed paraffin embedded medulloblastomas

BACKGROUND

Medulloblastoma has recently been found to consist of 4 molecularly and clinically distinct subgroups: WNT, Sonce hedgehog (SHH), Group 3, and Group 4. Deregulated microRNA expression is known to contribute to pathogenesis and has been shown to have diagnostic and prognostic potential in the classification of various cancers.

METHODS

Molecular subgrouping and microRNA expression analysis of 44 frozen and 59 formalin-fixed paraffin embedded medulloblastomas from an Indian cohort were carried out by real-time RT-PCR assay.

RESULTS

The differential expression of 9 microRNAs in the 4 molecular subgroups was validated in a set of 101 medulloblastomas. The tumors in the WNT subgroup showed significant (P < .0001) overexpression of miR-193a-3p, miR-224, miR-148a, miR-23b, and miR-365. Reliable classification of medulloblastomas into the 4 molecular subgroups was obtained using a set of 12 protein-coding genes and 9 microRNAs as markers in a real-time RT-PCR assay with an accuracy of 97% as judged by the Prediction Analysis of Microarrays. Age at diagnosis, histology, gender-related incidence, and the relative survival rates of the 4 molecular subgroups in the present Indian cohort were found to be similar to those reported for medulloblastomas from the American and European subcontinent. Non-WNT, non-SHH medulloblastomas underexpressing miR-592 or overexpressing miR-182 were found to have significantly inferior survival rates, indicating utility of these miRNAs as markers for risk stratification.

CONCLUSIONS

The microRNA based real-time PCR assay is rapid, simple, inexpensive, and useful for molecular classification and risk stratification of medulloblastomas, in particular formalin-fixed paraffin embedded tissues, wherein the expression profile of protein-coding genes is often less reliable due to RNA fragmentation.

A case of glioblastoma multiforme with long term survival: can we predict the outcome?

Glioblastoma Multiforme (GBM) presents a major challenge for a neurosurgeon as the most common primary malignant tumour of the central nervous system. The median life span after the diagnosis still remains between 6 months to 1 year even after gross total excision of the tumour. However, few patients survive long and develop recurrence after a substantial time interval. The exact reason behind the long term survival in GBM cases remains obscure. However, few predictors have been identified of late. Young age, p53 positivity, O6-methylguanine methyltransferase (MGMT) methylation, aggressive surgical resection and a good pre-operative Karnofsky Performance Score (KPS) have been identified with good survival rates in these select cases. Immunohistochemistry forms an integral part of a glioblastoma work up and it must be done in each and every case as it may provide crucial insights regarding prognosis. We report a rare case of glioblastoma multiforme with a long term survival of 20 years. This patient developed a frontal cystic tumour bilaterally in these 20 years and is still leading an active life. The clinical summary, imaging, histopathology, immunohistochemistry along with relevant literature have been discussed.