Complex lumbosacral spinal cord lipomas: A longitudinal study on outcomes from a Singapore children's hospital

BACKGROUND

Total/near-total resection (TR/NTR) of complex lumbosacral lipomas (CSL) is reported to be associated with better long-term functional outcomes and lower symptomatic re-tethering rates. We report our institutional experience for CSL resection in affected children.

METHODS

This is a single-institution, retrospective study. Inclusion criteria consist of patients with CSL with dorsal, transitional and chaotic lipomas based on Pang et al's classification. The study population is divided into 2 groups: asymptomatic patients with a normal preoperative workup referred to as 'prophylactic intent' and 'therapeutic intent' for those with pre-existing neuro-urological symptoms. Primary aims are to review factors that affect post-operative clean intermittent catheterization (CIC), functional outcomes based on Necker functional score (NFS), and re-tethering rates.

RESULTS

122 patients were included from 2000 to 2021. There were 32 dorsal lipomas (26.2 %), 74 transitional lipomas (60.7 %), and 16 chaotic lipomas (13.1 %). 82 % patients achieved TR/NTR. Favourable NFS at 1-year was 48.2 %. The re-tethering rate was 6.6 %. After multivariable analysis, post-operative CIC was associated with median age at surgery (p = 0.026), lipoma type (p = 0.029), conus height (p = 0.048) and prophylactic intent (p < 0.001). Next, extent of lipoma resection (p = 0.012) and the post-operative CSF leak (p = 0.004) were associated with re-tethering. Favourable NFS was associated with lipoma type (p = 0.047) and prophylactic intent surgery (p < 0.001).

CONCLUSIONS

Our experience shows that TR/NTR for CSL is a feasible option to prevent functional deterioration and re-tethering. Efforts are needed to work on factors associated with post-operative CIC.

Withdrawal notice to Spinal dysraphism-perspectives from a Southeast Asian paediatric neurosurgical unit: WNEU, 173 (2023) 20134

The Publisher regrets that this article is an accidental duplication of an article that has already been published in WNEU, 172 (2023) 20066, https://doi.org/10.1016/j.wneu.2023.01.070. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/policies/article-withdrawal.

Fibrofatty filum terminale: long-term outcomes from a Singapore children's hospital

OBJECTIVE

The role of prophylactic detethering a fibrofatty filum terminale (FFT) remains equivocal. Furthermore, long-term studies focusing on urological outcomes are sparse. The aims of this study were to present an institutional experience on the perioperative and long-term outcomes of FFT surgery and to assess for factors that contribute to postoperative clean intermittent catheterization (CIC).

METHODS

This was a single-institution, retrospective study conducted over a 20-year period. Patients younger than 19 years of age who underwent surgery for FFT were included. Variables of interest included patient demographics, clinical presentation, radiological findings, postoperative complications, and long-term need for CIC. Outcomes were measured using the Necker functional score and modified Hoffer Functional Ambulation scale score at 3, 6, and 12 months postdischarge.

RESULTS

A total of 164 surgeries were performed for FFT from 2000 to 2020. The median age at surgery was 1.1 years, and the mean follow-up duration was 8.3 years. There were 115 patients (70.1%) who underwent prophylactic-intent surgery and 49 patients (29.9%) who underwent therapeutic-intent surgery. The proportion of therapeutic-intent surgeries increased significantly with age percentiles (0-20th, 21.9%; 20th-40th, 9.1%; 40th-60th, 18.2%; 60th-80th, 36.4%; and 80th-100th, 63.6% [p < 0.001]). Thirty patients (18.3%) had an associated syndrome, the most common (n = 19, 11.6%) being VACTERL (vertebral defects, anal atresia, cardiac defects, tracheo-esophageal fistula, renal anomalies, and limb abnormalities). Forty-eight patients (29.3%) had an associated malformation (anorectal anomaly = 37, urogenital anomaly = 16, and sacral anomaly = 3). Cutaneous manifestation was the most common presentation (n = 96, 58.5%), followed by lower-limb neurological deficits (n = 21, 12.8%). A low-lying conus was present in 36.0% of patients (n = 59), and 16.5% had an associated syrinx (n = 27). There were 26 patients (18.8%) with an abnormal preoperative urodynamic study. Three patients (1.8%) had postoperative complications that required repeat surgery. There were no cases of CSF leakage. One patient (0.6%) developed retethering requiring another surgery. Postoperative CIC was required in 11 patients (6.7%). Multivariable analyses showed that an abnormal preoperative urodynamic study (adjusted OR 5.5 [95% CI 1.27-23.9], p = 0.023) and having an intraspinal syrinx (adjusted OR 5.29 [95% CI 1.06-26.4], p = 0.042) were associated with the need for CIC.

CONCLUSIONS

The authors' results demonstrate that detethering surgery for FFT is a relatively safe procedure and can be performed prophylactically. Nonetheless, the risks of postoperative CIC should be emphasized during the preoperative counseling process.

Spinal Dysraphism-Perspectives from a Southeast Asian Pediatric Neurosurgical Unit

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://doi.org/10.1016/j.wneu.2023.01.070. The duplicate article has therefore been withdrawn.

Tethered cord secondary to focal nondisjunction of the primary neural tube: experience from a Singapore children's hospital

PURPOSE

Tethered cord due to focal nondisjunction of primary neuralisation (FNPN) is a rare form of spinal dysraphism. We present our institutional experience in managing children diagnosed with FNPN.

MATERIALS AND METHODS

This is a single institution, retrospective study approved by the hospital ethics board. Patients below 18 years of age diagnosed with CDS, LDM or their mixed lesions, and subsequently underwent intervention by the Neurosurgical Service, KK Women's and Children's Hospital, are included.

RESULTS

From 2001 to 2021, 16 FNPN patients (50% males) were recruited. Eight of them had CDS (50.0%), seven had LDM (43.8%), and one patient had a mixed CDS and LDM lesion (6.2%). The average duration of follow up was 5.7 years and the mean age of surgery was 6 months old. Thirteen patients underwent prophylactic intent surgery (81.2%) and three had therapeutic intent surgery (18.8%). All patients did not have new neurological deficit or required repeat surgery for cord retethering. We observed that detethering surgery performed at or less than three months old was associated with having a wound infection (p = .022).

CONCLUSIONS

Our study reports that early recognition and timely intervention are mainstays of management for FNPN. We advocate a multi-disciplinary approach for good outcomes.

Decompressive surgery in abusive head injury: Experience from a Singapore children's hospital and a review of literature

PURPOSE

Abusive head trauma (AHT) is a major cause of morbidity and mortality in children. Studies on pediatric head injury observe that AHT patients often have a higher incidence of malignant cerebral oedema and, overall, worse prognosis. There are limited studies with a focus on the outcome of decompressive surgery in children with AHT. This is a study undertaken to review our institutional experience on the role of decompressive surgery in AHT patients and objectively assess its outcomes, in corroboration with current literature.

METHODS

This is an ethics-approved, retrospective study. Inclusion criteria consist of all children with a diagnosis of AHT managed by the Neurosurgical Service, KK Women's and Children's Hospital. Demographical and clinical variables are incorporated in the statistical analyses.

RESULTS

From 2011 to 2021, a total of 7 patients required decompressive surgery for AHT. Mean age of the cohort was 17.1 months (with the majority of patients being male (n = 5, 71.4%). During the follow-up period, there was 1 mortality (14.3%), 3 patients developed cerebral palsy (42.9%), and 3 patients had post-traumatic epilepsy (42.9%). With regards to functional outcome, 4 patients (57.1%) had a favorable KOSCHI score at 6 months follow-up.

CONCLUSION

Decompressive surgery in children with AHT presents with its own unique challenges. We therein present our neurosurgical experience in decompressive surgery for this extremely vulnerable group of patients. Given the potential role of decompressive surgery in AHT, the development of an objective marker to select such patients who may benefit most from intervention should be the way forward.

Paediatric brain tumours in Singapore: A 15-year epidemiological and outcome study

Paediatric brain tumours (PBTs) are the most common solid tumours in children. Previous publications reflect variations in incidence rates and frequency of histological types in different global populations. However, there are limited studies on the epidemiology of PBTs in Singapore. This study aims to summarise the epidemiology of paediatric brain tumours managed in Singapore. This is an ethics-approved retrospective study of all patients below 19 years old diagnosed with PBTs managed by Singapore's 2 tertiary paediatric neurosurgical centres, KK Women's and Children's Hospital (KKH) and the National University Hospital (NUH) over a 15-year period from 01 January 2002 to 31 December 2017. Data collected was analysed for age, gender, tumour characteristics, presenting complaints, location, treatment modalities, 1-year and 5-year overall survival (OS). A total of 396 patients were included. The mean age of diagnosis was 7.05 years (0.25-18; ± 4.83) and male-to-female ratio was 1.41:1. Top histological groups were astrocytic (30.6%), embryonal (26.0%), germ cell (11.1%), ependymoma (30, 7.58%) and craniopharyngioma (27, 6.82%). Outcomes included recurrence rate (31.2%), 1-year OS (89.5%) and 5-year OS (72.2%). Poorer 5-year OS were noted in embryonal tumours (47.0%; p < 0.001) and ependymoma (50.0%; p = 0.0074) patients. Of note, the following cohorts also had poorer OS at 5 years: supratentorial tumours (76.2%; p = 0.0426), radiotherapy (67.4%; p = 0.0467) and surgery (74.9%, HR; p < 0.001). Overall, our data reflects patient demographics, presenting complaints, treatment modalities and survival outcomes, that are comparable to other international paediatric neurosurgical centres.

Paediatric arachnoid cysts: Surgical outcomes from a Singapore children's hospital

Arachnoid cysts (AC) are reported to have a prevalence of up to 2.6% in children. Most AC remain indolent, but others may expand or rupture to cause life-threatening symptoms of raised intracranial pressure. Currently, there are 2 controversial topics with regards to the management of ACs: the indications for surgery and the choice of surgical procedure. We therein report our institution's neurosurgical experience for symptomatic AC over a 22-year period and corroborate our results with published literature. This is a single institution, retrospective study conducted at KK Women's and Children's Hospital from 01 January 1998 to 31 December 2019. A total of 38 patients with ACs that required surgery were recruited. The 3 most common anatomical locations were in the middle cranial fossa (40.5%), posterior fossa (24.3%) and interhemispheric (13.5%). Typical clinical presentations included symptoms of raised intracranial pressure (34.2%), obstructive hydrocephalus (28.9%) and AC rupture (21.1%). Surgical approaches included 17 craniotomy-based procedures, 7 endoscopic fenestrations, 11 cystoperitoneal shunts, 2 burrhole drainage operations and 1 excision of spinal AC. Thirteen patients (34.2%) underwent either another operation due to the lack of resolution of their AC-related symptoms or secondary to complications directly related to their initial surgery. Average length of followup from time of first operation was 84.1 months. Overall, our results demonstrate similarities in epidemiology, clinical presentation and surgical experience, in comparison to larger cohort studies. We advocate collaborative efforts to better understanding of the pathophysiology of paediatric ACs, particularly for deciding between the various surgical treatment modalities.

Cerebrospinal fluid cytokines in metastatic group 3 and 4 medulloblastoma

Background

Metastatic medulloblastoma (MB) portends a poor prognosis. Amongst the 4 molecular subtypes, Group 3 and Group 4 patients have a higher incidence of metastatic disease, especially involving the neuroaxis. At present, mechanisms underlying MB metastasis remain elusive. Separately, inflammation has been implicated as a key player in tumour development and metastasis. Cytokines and their inflammation-related partners have been demonstrated to act on autocrine and, or paracrine pathways within the tumour microenvironment for various cancers. In this study, the authors explore the involvement of cerebrospinal fluid (CSF) cytokines in Group 3 and 4 MB patients with disseminated disease.

Methods

This is an ethics approved, retrospective study of prospectively collected data based at a single institution. Patient clinicpathological data and corresponding bio-materials are collected after informed consent. All CSF samples are interrogated using a proteomic array. Resultant expression data of selected cytokines are correlated with each individual’s clinical information. Statistical analysis is employed to determine the significance of the expression of CSF cytokines in Group 3 and 4 patients with metastatic MB versus non-metastatic MB.

Results

A total of 10 patients are recruited for this study. Median age of the cohort is 6.6 years old. Based on Nanostring gene expression analysis, 5 patients have Group 3 as their molecular subtype and the remaining 5 are Group 4. There are 2 non-metastatic versus 3 metastatic patients within each molecular subtype. Proteomic CSF analysis of all patients for both subtypes show higher expression of CCL2 in the metastatic group versus the non-metastatic group. Within the Group 3 subtype, the MYC-amplified Group 3 MB patients with existing and delayed metastases express higher levels of CXCL1, IL6 and IL8 in their CSF specimens at initial presentation. Furthermore, a longitudinal study of metastatic Group 3 MB observes that selected cytokines are differentially expressed in MYC-amplified metastatic Group 3 MB, in comparison to the non-MYC amplified metastatic Group 3 MB patient.

Conclusion

This study demonstrates higher expression of selected CSF cytokines, in particular CCL2, in metastatic Group 3 and 4 MB patients. Although our results are preliminary, they establish a proof-of-concept basis for continued work in a larger cohort of patients affected by this devastating disease.

Extraneural metastatic paediatric glioblastoma: Case report and literature review

The incidence of paediatric glioblastoma is uncommon in comparison to their adult counterpart. Even more infrequent are extraneural metastases in glioblastoma. A previously well 14-year-old female presented with progressive right hemiparesis secondary to a left fronto-temporal lobe glioblastoma (WHO IV). She underwent successful gross total resection for her brain tumour. Prior to commencement of her adjuvant treatment, she developed tumour recurrence associated with intra-lesional haemorrhage. Although she underwent a second surgery, the patient developed bilateral malignant pleural effusion secondary to extraneural pulmonary metastases. Early awareness of its existence enables prompt diagnosis for this devastating disease. The authors emphasize the urgent need for international collaborations to work together for children affected by this challenging brain tumour.

Sporadic Meningioangiomatosis Presenting as a Middle Cranial Fossa Arachnoid Cyst

BACKGROUND

Meningioangiomatosis is an extremely rare meningovascular disease of the central nervous system that is characterized by the proliferation of leptomeninges, cortical vessels, and perivascular spindled cells. Although it is a benign, neoplastic disorder that carries a good prognosis after surgical excision, initial diagnosis may be challenging as radiologic findings are often variable and nonspecific.

CASE DESCRIPTION

In this report, we describe an unusual presentation of meningioangiomatosis presenting as a symptomatic middle cranial fossa arachnoid cyst.

CONCLUSIONS

In view of the unexpected diagnosis and infrequency of this condition, the case is discussed in collaboration with current literature and management strategies.

Paediatric meningiomas in Singapore - Case series of a rare entity

Paediatric meningiomas are extremely rare. These tumours constitute only 2 to 3% of all childhood brain tumours. Despite similarities in histological features between PMs and their adult counterparts, there are important distinctions between them. In this case series, the authors describe their experience in paediatric meningiomas in Singapore's 2 children's hospitals from 1998 to 2018. The primary aim of this retrospective study is to evaluate the clinical, radiological and pathological characteristics, and associated outcomes of paediatric patients diagnosed with meningioma managed in our local institutions. Following that, the study's findings are secondary aims are corroborated with published literature. A total of 10 patients (4 males and 6 females) were identified for this study within the period of 01 January 1998 to 31 December 2018. Their ages ranged from 1 year old to 18 years old (median age 10.5 years old). Two of the patients had NF1 and NF2 respectively. There were 9 intracranial and 1 intraspinal paediatric meningiomas. Seven patients achieved gross total resection and 3 patients had subtotal resection. Eight patients did not have tumour recurrence or increase in size of tumour remnant during the course of their follow-up. In congruency with the literature, up to 40% of our patients had higher grade meningiomas and 55.6% had large tumour volumes more than 30 cm³. Owing to the paucity of knowledge for this unusual tumour, the authors emphasize the need for closer surveillance and in-depth genomic studies to identify novel therapies for this challenging condition.

Use of an Offsite Intraoperative MRI Operating Theater for Pediatric Brain Tumor Surgery: Experience from a Singapore Children's Hospital

BACKGROUND

Intraoperative magnetic resonance imaging (iMRI) has been recognized as a useful adjunct for brain tumor surgery in pediatric patients. There is minimal data on the use of an offsite intraoperative magnetic resonance imaging operating theater (iMRI OT), whereby vehicle transfer of patients is involved. The primary aim of this study is to validate the feasibility of perioperative patient transfer to use an offsite iMRI OT for patients with pediatric brain tumor. Secondary objectives include the assessment of tumor resection efficacy and perioperative outcomes in our patient cohort.

METHODS

This is a retrospective, single-institution clinical study of prospectively collected data from Singapore's largest children hospital. Variables of interest include issues encountered during interhospital transfer, achievement of surgical aims, length of stay in hospital, and postoperative complications. Our findings were compared with results of related studies published in the literature.

RESULTS

From January 1, 2009 to December 31, 2018, a total of 35 pediatric operative cases were performed in our offsite iMRI OT. Within this cohort, 24 of these were brain tumor surgery cases. For all the patients in this study, use of the iMRI OT influenced intraoperative decisions. Average ambulance transport time from parent hospital to the iMRI OT was 30.5 minutes, and from iMRI OT back to the parent hospital after surgery was 27.7 minutes. The average length of hospitalization stay was 7.9 days per patient. There were no ferromagnetic accidents during perioperative iMRI scanning and no airway/hemodynamic incidents in patients encountered during interhospital transfer.

CONCLUSIONS

In our local context, the use of interhospital transfers for access to iMRI OT is a safe and feasible option in ensuring good patient outcomes for a select group of patients with pediatric brain tumors.

The Seow Operative Score (SOS) as a decision-making adjunct for paediatric Chiari I malformation: a preliminary study

PURPOSE

The natural history of Chiari I malformation (C1M) in the paediatric population is poorly understood. There are conflicting reports with regards to surgical indications, operative techniques and peri-operative prognostic indicators. In this paper, we report our institutional experience in the management of paediatric C1M.

METHODS

The workflow process which includes preferred imaging modalities, surgical techniques and indications for intervention is discussed. In particular, we describe one of our current projects-an in-house designed Seow Operative Score (SOS) as a feasibility scoring system for neurosurgical intervention in our local cohort of paediatric C1M patients.

RESULTS

In our series, we have 2 groups: 10 non-operated patients versus 19 operated patients. In the non-operated group, the majority of patients had a SOS of 0 to 1. One patient had a score of 2.5 and was kept under close surveillance. Follow-up imaging demonstrated resolution of the cerebellar herniation and intraspinal syrinx. In the operated group, 17 patients had a SOS of 3 or more. Two patients had a SOS of 2. For these 2, 1 developed progressive symptoms, and the other had an extensive cervico-thoracic syrinx. Decision was made for surgery after a period of surveillance.

CONCLUSIONS

In this paper, we report our institutional experience in managing paediatric C1M and, at the same time, highlight salient points of our practices. Meanwhile, we advocate collective global efforts and in-depth research for better disease understanding of this challenging condition.

Spontaneous Intracranial Hypotension Presenting As Cervicogenic Headache: Case Report and Review of Literature

BACKGROUND

Spontaneous intracranial hypotension is uncommon. There is a lack of understanding of its exact pathophysiology along with significant variability in its clinical management.

CASE DESCRIPTION

The authors report the case of a previously well man with cervicogenic headache associated with magnetic resonance imaging features of intracranial hypotension. The salient features of this case include the details of various treatments prescribed for his condition and the therapeutic difficulties encountered.

CONCLUSION

Owing to the infrequency of the diagnosis, the challenges of clinical management for this patient are discussed in relationship to current literature. Next, the highlights of this unusual case in an individual add to the growing body of literature reports for better understanding of this disease.

Right middle cerebral artery infarct after minor head trauma in an infant: Case report and literature review

Ishaemic stroke (IS) in the paediatric population is extremely rare. In this age group, the occurrence of IS often concurs with underlying congenital heart disease, haematological, metabolic or immunological conditions. In contrast, the association between IS and minor head injury in children has been sparse in current literature. The authors report a case of a healthy 9-month-old male who was found to have a right middle cerebral artery territory infarct after a minor head injury. An extensive medical workup was performed, and it was negative for any previously undiagnosed co-morbidities. Given the paucity of such cases, the condition and its management are discussed in corroboration with current literature.

Primary paediatric epidural sarcomas: molecular exploration of three cases

Background

Primary paediatric epidural sarcomas are extremely rare. Overall, there remains a paucity of knowledge in paediatric epidural sarcomas owing to the infrequent number of cases. The Archer FusionPlex Sarcoma Kit (ArcherDX, Inc) is a next-generation sequencing assay that has been reported to be a useful technique to detect recurrent fusion in sarcomas. We report the molecular exploration of 3 primary paediatric epidural sarcomas—one in the cranium (mesenchymal chondrosarcoma) and 2 in the spine (mesenchymal chondrosarcoma and Ewing sarcoma respectively).

Case presentation

This is a study approved by the hospital ethics board. Clinico-pathological information from 3 consenting patients with primary epidural sarcomas was collected. These selected tumours are interrogated via Archer FusionPlex Sarcoma Kit (ArcherDX, Inc) for genomic aberrations. Results were validated with RT-PCR and Sanger sequencing. All findings are corroborated and discussed in concordance with current literature. Our findings show 2 variants of the HEY1-NCOA2 gene fusion: HEY1 (exon 4)-NCOA2 (exon 13) and HEY1 (exon 4)-NCOA2 (exon 14), in both mesenchymal chondrosarcoma patients. Next, the Ewing sarcoma tumour is found to have EWSR1 (exon 10)-FLI1 (exon 8) translocation based on NGS. This result is not detected via conventional fluorescence in situ testing.

Conclusions

This is a molecularly-centered study based on 3 unique primary paediatric epidural sarcomas. Our findings to add to the growing body of literature for these exceptionally rare and malignant neoplasms. The authors advocate global collaborative efforts and in-depth studies for targeted therapy to benefit affected children.

Management of brain abscesses: where are we now?

INTRODUCTION

Brain abscesses affect all age groups and are not peculiar to a particular country, race, or geographical location. It is a disease that, in the past, carried a high morbidity and mortality. With improvements in medical technology and expertise, outcomes have improved tremendously. The causative organisms vary vastly and have evolved with time. Treatment of brain abscesses is primarily with antimicrobial therapy but surgery plays a vital role in achieving better outcomes.

CONTENT

In this article, we review the literature to find out how the epidemiology of this disease has changed through the years and re-visit the basic pathological process of abscess evolution and highlight the new research in the biochemical pathways that initiate and regulate this process. We also highlight how magnetic resonance imaging and its various modalities have improved diagnostic accuracy. Finally, we discuss the pros and cons of traditional open surgery versus newer minimally invasive methods.

Intra-operative cerebrospinal fluid sampling versus post-operative lumbar puncture for detection of leptomeningeal disease in malignant paediatric brain tumours

Introduction

Leptomeningeal disease is a feared sequelae of malignant paediatric brain tumours. Current methods for its detection is the combined use of cranio-spinal MRI, and CSF cytology from a post-operative lumbar puncture. In this study, the authors hypothesize that CSF taken at the start of surgery, either from an external ventricular drain or neuroendoscope will have equal sensitivity for positive tumour cells, in comparison to lumbar puncture. Secondary hypotheses include positive correlation between CSF cytology and MRI findings of LMD. From a clinical perspective, the key aim of the study was for affected paediatric patients to avoid an additional procedure of a lumbar puncture, often performed under anaesthesia after neurosurgical intervention.

Methods

This is single-institution, retrospective study of paediatric patients diagnosed with malignant brain tumours. Its main aim was to compare cytological data from CSF collected at the time of surgery versus data from an interval lumbar puncture. In addition, MRI imaging of the same cohort of patients was examined for leptomeningeal disease and corroborated against CSF tumour cytology findings.

Results

Thirty patients are recruited for this study. Data analysis demonstrates a statistically significant association between our intra-operative CSF and LP sampling. Furthermore, our results also show for significant correlation between evidence of leptomeningeal disease on MRI findings versus intra-operative CSF positivity for tumour cells.

Conclusion

Although this is a retrospective study with a limited population, our data concurs with potential to avoid an additional procedure for the paediatric patient diagnosed with a malignant brain tumour.

Cystic Cavernoma of Fourth Ventricle in Pediatric Patient

BACKGROUND

Cystic cerebral cavernomas belong to a rare subset of cavernous malformations in the brain. At present, there is limited information with regard to the demographics and etiology of this condition.

CASE DESCRIPTION

The authors present a case of a previously well 13-year-old male who presented with symptoms secondary to a cystic lesion of the fourth ventricle compressing on his brainstem. He underwent stereotactic aspiration of the cystic lesion and insertion of an Ommaya reservoir in the same setting. Postoperatively, his symptoms improved. The cyst fluid did not yield any positive cytology or culture results. A repeat MRI brain did not demonstrate evidence of any underlying lesion. However, the patient was readmitted for hemorrhage into the region of his previous fourth ventricular lesion. Surgical evacuation of the haematoma was performed and intraoperative tissue was sent for pathological interrogation. The final histology reported a cavernoma.

CONCLUSIONS

This is an unusual presentation of an intracranial vascular anomaly in a pediatric patient. Key features of the case include the diagnostic dilemma and management challenges faced from a neurosurgical perspective.

Prognostic value of medulloblastoma extent of resection after accounting for molecular subgroup: a retrospective integrated clinical and molecular analysis

Background

Incomplete surgical resection of medulloblastoma is controversially considered a marker of high-risk disease; driving aggressive surgical resections, “second-look” surgeries, and/or intensified chemoradiotherapy. All prior publications evaluating the clinical importance of extent of resection (EOR) failed to account for molecular subgroup. We analysed the prognostic value of EOR across 787 medulloblastoma samples in a subgroup-specific manner.

Methods

We retrospectively identified patients from Medulloblastoma Advanced Genomics International Consortium (MAGIC) centres with a histological diagnosis of medulloblastoma and complete extent of resection and survival data. Specimens were collected from 35 international institutions. Medulloblastoma subgroup affiliation was determined using nanoString gene expression profiling on frozen or formalin-fixed paraffin-embedded tissues. Extent of resection (EOR) based on post-operative imaging was classified as gross total (GTR), near total (NTR, <1·5cm²), or subtotal (STR, ≥ 1·5cm²). Overall survival (OS) and progression-free survival (PFS) multivariable analyses including subgroup, age, metastatic status, geographical location of therapy (North America/Australia vs world), and adjuvant therapy regimen were performed. The primary endpoint was the impact of surgical EOR by molecular subgroup and other clinical variables on OS and PFS.

Findings

787 medulloblastoma patients (86 WNT, 242 SHH, 163 Group 3, and 296 Group 4) were included in a multivariable Cox model of PFS and OS. The marked benefit of EOR in the overall cohort was greatly attenuated after including molecular subgroup in the multivariable analysis. There was an observed PFS benefit of GTR over STR (hazard ration [HR] 1·45, 95% CI; 1·07–1·96, p=0·02) but there was no observed PFS or OS benefit of GTR over NTR (HR 1·05, 0·71–1·53, p=0·82 and HR 1·14, 0·75–1·72, p=0.55). There was no statistically significant survival benefit to greater EOR for patients with WNT, SHH, or Group 3 patients (HR 1·03, 0·67–1·58, p=0·9 for STR vs. GTR). There was a PFS benefit for GTR over STR in patients with Group 4 medulloblastoma (HR1·97, 1·22–3·17, p=0·01), particularly those with metastatic disease (HR 2·22, 1–4·93, p=0·05). A nomogram based on this multivariable cox proportional hazards model shows the comparably smaller impact of EOR on relative risk for PFS and OS than subgroup affiliation, metastatic status, radiation dose, and adjuvant chemotherapy.

Interpretation

The prognostic benefit of EOR for patients with medulloblastoma is attenuated after accounting for molecular subgroup affiliation. Although maximal safe surgical resection should remain the standard of care, surgical removal of small residual portions of medulloblastoma is not recommended when the likelihood of neurological morbidity is high as there is no definitive benefit to GTR over NTR. Our results suggest a re-evaluation of the long-term implications of intensified craniospinal irradiation (36 Gy) in children with small residual portions of medulloblastoma.

Funding

Funding Canadian Cancer Society Research Institute, Terry Fox Research Institute, Canadian Institutes of Health Research, National Institutes of Health, Pediatric Brain Tumor Foundation, Garron Family Chair in Childhood Cancer Research.

Characterization of anaplastic lymphoma kinase-positive medulloblastomas

Medulloblastomas are the most common pediatric malignant primary brain tumor. To our knowledge, there are no known critical and druggable tyrosine kinases in medulloblastomas, precluding the use of established tyrosine kinase inhibitors that have shown efficacy in other tumor types. We studied the expression of anaplastic lymphoma kinase (ALK), a well-characterized tyrosine kinase and drug target, in a cohort of medulloblastomas by immunohistochemistry, and identified three ALK-positive cases. Mutational analyses did not reveal a definite underlying genetic mechanism for the ALK expression, although one of the cases showed increased ALK copy number. Our findings have clinical implications and warrant further pharmacological and functional studies, as well as evaluation in larger patient cohorts, to fully characterize the value of ALK as a prognostic and predictive therapeutic marker in medulloblastomas.

Pediatric de novo cerebral AVM: report of two cases and review of literature

PURPOSE

Cerebral arteriovenous malformation (AVM) is traditionally thought of as a congenital diagnosis. In recent years, there has been infrequent reports of this neurovascular condition presenting as de novo entities.

METHODS

The authors report two cases of pediatric patients who present with de novo cerebral AVMs. In both cases, the patients had magnetic resonance imaging (MRI) of the brain done as part of the work-up for first-onset seizures. At that point in time, the scans were unremarkable. After a latent period of approximately 6 and 9 years respectively, a repeated MRI brain scan showed evidence of de novo AVM for each patient.

RESULTS

Both patients did not have radiological evidence of cerebral AVM during their first presentation of seizures. However, a repeated MRI brain scan after a period of 6 and 9 years demonstrated new findings of cerebral AVM for each patient.

CONCLUSIONS

Currently, the disease of cerebral de novo AVM remain as an ambiguous condition that is poorly understood. With the advances in molecular diagnostics, there are possibilities of exploring biochemical profiles for better understanding of the origin of cerebral AVMs. However, in the meantime, owing to the unpredictable nature of cerebral AVMs, clinicians should have increased awareness of this unique condition. This is especially important, as definitive treatment is available to prevent devastating neurological sequelae from cerebral AVM rupture.

Benign scalp lump as an unusual presentation of extranodal Rosai-Dorfman disease

Background:

Rosai–Dorfman disease (RDD) is a rare benign histioproliferative disease. It is typically characterized by benign histiocyte proliferation with lymphadenopathy, fever, and leukocytosis and was first described in 1969 by Rosai and Dorfman. Extranodal involvement has been reported in approximately up to 43% of the cases with isolated central nervous system (CNS) manifestations being even rarer.

Case Description:

We report our management of a 41-year-old female with extranodalpurely CNS RDD presenting as a benign scalp lump. Her lump progressed from an asymptomatic benign lesion to one causing localized cerebral edema. Treatment was surgical excision of both the cervical and CNS lesions achieving complete removal of the lesions and resolution of her symptoms.

Conclusion:

RDD is a rare condition and isolated CNS RDD is even less common. Benign scalp lumps have a myriad of differential diagnoses, but RDD should be a consideration in the presence of preexisting RDD lesions at other sites given its potential to progress and result in morbidity. It is imperative to be aware that symptoms may be especially deceiving as the absence of lymphadenopathy may point away from RDD as the diagnosis.