Prognosis of cerebellar astrocytomas in children

Postoperative speech impairment and cranial nerve deficits after secondary surgery of posterior fossa tumours in childhood: a prospective European multicentre study

PURPOSE

Brain tumours constitute 25% of childhood neoplasms, and half of them are in the posterior fossa. Surgery is a fundamental component of therapy, because gross total resection is associated with a higher progression-free survival. Patients with residual tumour, progression of residual tumour or disease recurrence commonly require secondary surgery. We prospectively investigated the risk of postoperative speech impairment (POSI) and cranial nerve dysfunction (CND) following primary and secondary resection for posterior cranial fossa tumours.

METHODS

In the Nordic-European study of the cerebellar mutism syndrome, we prospectively included children undergoing posterior fossa tumour resection or open biopsy in one of the 26 participating European centres. Neurological status was assessed preoperatively, and surgical details were noted post-operatively. Patients were followed up 2 weeks, 2 months and 1 year postoperatively. Here, we analyse the risk of postoperative speech impairment (POSI), defined as either mutism or reduced speech, and cranial nerve dysfunction (CND) following secondary, as compared to primary, surgery.

RESULTS

We analysed 426 children undergoing primary and 78 undergoing secondary surgery between 2014 and 2020. The incidence of POSI was significantly lower after secondary (12%) compared with primary (28%, p = 0.0084) surgery. In a multivariate analysis adjusting for tumour histology, the odds ratio for developing POSI after secondary surgery was 0.23, compared with primary surgery (95% confidence interval: 0.08-0.65, p = 0.006). The frequency of postoperative CND did not differ significantly after primary vs. secondary surgery (p = 0.21).

CONCLUSION

Children have a lower risk of POSI after secondary than after primary surgery for posterior fossa tumours but remain at significant risk of both POSI and CND. The present findings should be taken in account when weighing risks and benefits of secondary surgery for posterior fossa tumours.

The Utility of Intraoperative Magnetic Resonance Imaging in the Resection of Cerebellar Hemispheric Pilocytic Astrocytomas: A Cohort Study

BACKGROUND

The mainstay of treatment for cerebellar pilocytic astrocytomas in the pediatric population is surgery. The use of intraoperative magnetic resonance imaging (iMRI) as a surgical adjunct may lower the likelihood of reoperation. Studies have examined iMRI in heterogenous tumor populations, but few have looked at single pathologies.

OBJECTIVE

To compare iMRI vs non-iMRI for hemispheric cerebellar pilocystic astrocytomas, specifically looking at revision surgeries and residual disease in follow-up.

METHODS

Retrospective review of medical records for 60 sequential patients with cerebellar hemispheric pilocytic astrocytoma at a single institution was conducted. Thirty-two patients with cerebellar pilocytic astrocytoma underwent surgery without iMRI, whereas 28 patients underwent surgical resection with iMRI. All patients had at least 3-year follow-up.

RESULTS

There were no significant differences between the patient populations in age, tumor size, or need for cerebrospinal fluid diversion between groups. Operative time was shorter without iMRI (without iMRI 4.4 ± 1.3 hours, iMRI 6.1 ± 1.5, P = .0001). There was no significant difference in the patients who had repeat surgery within 30 days (9% without iMRI, 0% iMRI, P = .25), residual disease at 3 months (19% without iMRI, 14% iMRI, P = .78), or underwent a second resection beyond 30 days (9% without iMRI, 4% iMRI, P = .61). There were more total reoperations in the group without iMRI, although this did not reach significance (19% vs 4%, P = .11).

CONCLUSION

For hemispheric cerebellar pilocytic astrocytomas, iMRI tended to leave less residual and fewer reoperations; however, neither of these outcomes achieved statistical significance leaving utilization to be determined by the surgeon.

Multifocal Infratentorial Pilocytic Astrocytoma in an Adult Patient

BACKGROUND

Pilocytic astrocytoma is a benign glial tumor typically presenting in children. It is rare for adults to present with pilocytic astrocytoma and even less likely to manifest with multiple foci of lesions especially in nonoptic or hypothalamic locations.

CASE DESCRIPTION

Our patient was a 37-year old man presenting with varied cranial neuropathies, cerebellar dysfunction, and long tract signs, with imaging demonstrating 3 discrete ill-defined contrast-enhancing lesions affecting the cerebellar peduncles, brainstem, and cervicomedullary junction. Neuronavigation-guided biopsy confirmed World Health Organization grade 1 pilocytic astrocytoma; the patient was treated with radiotherapy.

CONCLUSIONS

To our knowledge, we believe this is the first reported case with multifocal infratentorial pilocytic astrocytoma on presentation in an adult patient in the absence of a prior history of associated risk factors such as neurofibromatosis 1 or chemoradiotherapeutic intervention.

Pediatric cerebellar pilocytic astrocytoma presenting with spontaneous intratumoral hemorrhage

Pilocytic astrocytomas (PAs) are benign glial tumors and one of the most common childhood posterior fossa tumors. Spontaneous intratumoral hemorrhage in PAs occurs occasionally, in about 8-20% of cases. Cerebellar hemorrhages in pediatric population are rare and mainly due to head injuries, rupture of vascular malformations, infections, or hematological diseases. We have investigated the still controversial and unclear pathophysiology underlying intratumoral hemorrhage in PAs. Bleeding in low-grade tumors might be related to structural abnormalities and specific angio-architecture of tumor vessels, such as degenerative mural hyalinization, "glomeruloid" endothelial proliferation, presence of encased micro-aneurysms, and glioma-induced neoangiogenesis. The acute hemorrhagic presentation of cerebellar PA in childhood although extremely uncommon is of critical clinical importance and necessitates promptly treatment. We described a case of hemorrhagic cerebellar PA in a 9-year-old child and reviewed the English-language literature that reported spontaneous hemorrhagic histologically proven cerebellar PA in pediatric patients (0-18 years). According to our analysis, the mortality was not related to symptom onset, tumor location, hemorrhage distribution, presence of acute hydrocephalous, and timing of surgery, while the GCS at hospital admission resulted to be the only statistically significant prognostic factor affecting survival outcome. The abrupt onset of signs and symptoms of acute hydrocephalous and consequent raised intracranial pressure are life-threatening conditions, which need emergent medical and neurosurgical treatments. At a later time, the identification of posterior fossa hemorrhage etiology is crucial to select the appropriate treatment and address the surgical strategy, optimizing the postoperative results.

Securing Hemostasis in Pediatric Low-Grade Posterior Cerebral Fossa Tumors: The Value of Thrombin-Gelatin Hemostatic Matrix

PURPOSE

We report our preliminary experience concerning the use of thrombin-gelatin hemostatic matrix to strengthen the final hemostasis after posterior fossa low-grade tumor surgery in children. To our knowledge, this is the first report regarding the use of hemostatic matrix in pediatric neurosurgery.

MATERIALS AND METHODS

Between 2012 and 2016, twenty-three patients underwent posterior fossa surgery for low-grade gliomas in our department. The mean age was 6.35 years; 12 patients were female and 11 male. Histology revealed pilocytic astrocytoma in 15 cases, ependymoma in 7 cases, and gangliocytoma in 1 case. At the end of the surgery, effective hemostasis was achieved using standard methods and, in order to strengthen the final hemostasis, we used a thrombin-gelatin hemostatic matrix. In all of the cases a postoperative MRI was performed within 24 after the surgery; during hospitalization the patients underwent a clinical evaluation. Moreover, blood samples were taken to evaluate inflammatory parameters, hemoglobin, and sodium, and kidney and liver tests were performed according to the standard protocol.

RESULTS

The postoperative MRI did not show any complications imputable to the matrix. Dur ing radiological and clinical follow-up none of the patients showed any delayed complications related to the matrix.

CONCLUSIONS

In our practice we found thrombin-gelatin hemostatic matrix sealant to be a valid and safe tool for strengthening hemostasis in pediatric low-grade posterior fossa surgery.

Transcriptional profiles of pilocytic astrocytoma are related to their three different locations, but not to radiological tumor features

Background

Pilocytic astrocytoma is the most common type of brain tumor in the pediatric population, with a generally favorable prognosis, although recurrences or leptomeningeal dissemination are sometimes also observed. For tumors originating in the supra-or infratentorial location, a different molecular background was suggested, but plausible correlations between the transcriptional profile and radiological features and/or clinical course are still undefined. The purpose of this study was to identify gene expression profiles related to the most frequent locations of this tumor, subtypes based on various radiological features, and the clinical pattern of the disease.

Methods

Eighty six children (55 males and 31 females) with histologically verified pilocytic astrocytoma were included in this study. Their age at the time of diagnosis ranged from fourteen months to seventeen years, with a mean age of seven years. There were 40 cerebellar, 23 optic tract/hypothalamic, 21 cerebral hemispheric, and two brainstem tumors. According to the radiological features presented on MRI, all cases were divided into four subtypes: cystic tumor with a non-enhancing cyst wall; cystic tumor with an enhancing cyst wall; solid tumor with central necrosis; and solid or mainly solid tumor. In 81 cases primary surgical resection was the only and curative treatment, and in five cases progression of the disease was observed. In 47 cases the analysis was done by using high density oligonucleotide microarrays (Affymetrix HG-U133 Plus 2.0) with subsequent bioinformatic analyses and confirmation of the results by independent RT-qPCR (on 39 samples).

Results

Bioinformatic analyses showed that the gene expression profile of pilocytic astrocytoma is highly dependent on the tumor location. The most prominent differences were noted for IRX2, PAX3, CXCL14, LHX2, SIX6, CNTN1 and SIX1 genes expression even within different compartments of the supratentorial region. Analysis of the genes potentially associated with radiological features showed much weaker transcriptome differences. Single genes showed association with the tendency to progression.

Conclusions

Here we have shown that pilocytic astrocytomas of three different locations can be precisely differentiated on the basis of their gene expression level, but their transcriptional profiles does not strongly reflect the radiological appearance of the tumor or the course of the disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1810-z) contains supplementary material, which is available to authorized users.

Pediatric cerebellar astrocytoma: a review

INTRODUCTION

Cerebellar astrocytomas (CA) are one of the most common posterior fossa tumors in children. The vast majority is low grade, and prognosis for long-term survival is excellent.

METHODS

Recent literature about CA was reviewed to provide an up to date overview of the epidemiology, pathology, molecular and cell biology, diagnosis, presentation, management, and long-term outcomes.

RESULTS

Surgical resection remains the first-line treatment with complete removal of the tumor the goal. However, even when only subtotal resection has been achieved, there is a significant chance that the tumor will remain stable or will regress spontaneously. Adjuvant chemotherapy is reserved for those tumors that progress despite surgery, and more personalized chemotherapy is being pursued with better understanding of the molecular genetics of this tumor. Radiotherapy has generally not been recommended, but stereotactic radiotherapy and conformal proton beam radiotherapy may be reasonable options in the setting of relapse or progression. In the long term, permanent neurologic deficits, mainly cerebellar dysfunction, are common, but quality of life and cognitive function are generally good.

CONCLUSIONS

Low-grade CA remains primarily a surgical disease, with excellent survival rates. Care must be taken with surgery and adjuvant treatments to preserve neurologic function to allow for optimal outcomes in the long term.

Pure Neuroendoscopic Resection of Cystic Cerebellar Tumors

BACKGROUND

We describe the resection of cerebellar cystic tumors using pure neuroendoscopy. This technique consists of performing all of the procedures under an endoscopic view, with the instruments introduced into the operative field coaxially to the endoscope through a trocar.

CASE DESCRIPTION

Three cases of cerebellar cystic lesions (two pilocytic astrocytomas and one hemangioblastoma) were approached using the pure neuroendoscopic technique. Under general anesthesia and prone positioning, a suboccipital burr hole was created. The endoscope was introduced into the tumor cavity, and a reddish nodule was identified. The monopolar electrode was used to coagulate and dissect the surrounding nodular tissue. Grasping forceps were used to remove the nodule. There were no complications related to tumor removal, and the patients recovered from their symptoms. The follow-up images showed reduction of the cavity with no contrast enhancement.

CONCLUSION

The pure neuroendoscopic technique was shown to be minimally invasive and a successful and secure method to treat cystic cerebellar tumors.

p53 in neurodegenerative diseases and brain cancers

More than thirty years elapsed since a protein, not yet called p53 at the time, was detected to bind SV40 during viral infection. Thousands of papers later, p53 evolved as the main tumor suppressor involved in growth arrest and apoptosis. A lot has been done but the protein has not yet revealed all its secrets. Particularly important is the observation that in totally distinct pathologies where apoptosis is either exacerbated or impaired, p53 appears to play a central role. This is exemplified for Alzheimer's and Parkinson's diseases that represent the two main causes of age-related neurodegenerative affections, where cell death enhancement appears as one of the main etiological paradigms. Conversely, in cancers, about half of the cases are linked to mutations in p53 leading to the impairment of p53-dependent apoptosis. The involvement of p53 in these pathologies has driven a huge amount of studies aimed at designing chemical tools or biological approaches to rescue p53 defects or over-activity. Here, we describe the data linking p53 to neurodegenerative diseases and brain cancers, and we document the various strategies to interfere with p53 dysfunctions in these disorders.

Neurological morbidity of surgical resection of pediatric cerebellar astrocytomas

BACKGROUND

Review of children with low-grade cerebellar astrocytoma (LGCA) prior to 1992 showed a 98% rate of gross total resection (GTR) but a concerning incidence of permanent neurological dysfunction. The purpose of this study was to determine the rate of GTR of LGCA since 1992 and frequency of neurologic injury.

METHODS

Retrospective review of children with LGCA was performed. CT/MR scans were rereviewed to assess extent of resection. Primary outcomes included incidence of GTR and incidence of permanent new neurological deficits. Other outcomes included late effects severity score (LESS), Bloom score for functional status, and educational assessment.

RESULTS

Of 50 LGCA, GTR was achieved in 38 (76%) compared to 43 of 44 (98%) prior to 1992 (p < 0.004). Permanent new neurologic deficits from surgery occurred in 16% compared to 18% in the prior era (p = 0.61). For 35 patients operated on by the 2 surgeons in the prior study, 74% had GTR, with permanent neurological deficits in 8.6%. At latest follow-up, all patients were alive, 16% with residual tumor. LESS was two or less (mild or no deficit) in 94%. Bloom score was one or two (no or mild disability) in 90%. Eighty-six percent attended normal school.

CONCLUSIONS

Less aggressive resection of LGCA in children may reduce postoperative neurologic deficits in the hands of the same surgeons as in the prior study but not overall at our institution. The good long-term outcomes suggest that it may be appropriate to do incomplete resection rather than risk additional neurological deficit.

Arrested growth and spontaneous tumor regression of partially resected low-grade cerebellar astrocytomas in children

PURPOSE

The prognosis of children with low-grade cerebellar astrocytoma who have partial resection of tumor is largely unpredictable. The purpose of this study was to review the long-term outcome of such patients.

METHODS

The medical charts, imaging findings, operative notes, histopathological reports, and survival times of 12 patients with cerebellar astrocytoma were reviewed.

RESULTS

Five patients had total resection and seven had partial resection. Nine patients had grade I histology and three patients had grade II. Follow-up duration ranged from 3 to 25 years. Among the seven patients with residual tumor, five had tumor progression, one had arrested tumor growth, and one had spontaneous tumor regression. Five patients with partial resection received radiotherapy and three had malignant transformation of tumor during follow-up. Six patients, including five who had partial resection, underwent a second operation. One patient with partial resection died of pneumonia 23 years after surgery.

CONCLUSIONS

Patients with complete tumor resection had a better prognosis than patients with partial resection. For patients with partial resection, we recommend a "wait and see" policy with surveillance using MRI. The phenomenon of arrested tumor growth and spontaneous tumor regression in patients with cerebellar astrocytoma who have subtotal resection warrants further study.

Management of posterior fossa gliomas in children

Brain tumours form the most common type of solid tumour in children and more that 50% of these are infratentorial. Cerebellar astrocytomas and brain stem gliomas are the commonest posterior fossa glial tumours in children. Cerebellar astrocytomas represent up to 10% of all primary brain tumours and up to 25% of posterior fossa tumors in children, with Low grade gliomas forming the commonest of the cerebellar gliomas. They commonly present with symptoms and signs of raised intracranial pressure due to obstructive hydrocephalus. Radiologically they may be solid or cystic with or without a mural nodule. Surgical excision is the mainstay of treatment and forms the most consistent factor influencing progression free and long term survival. While majority of the tumours are pilocytic astrocytomas, they may also be fibrillary astrocytomas or even high grade tumours. Tumour histology does not appear to be an independent factor in the prognosis of these children, and therefore no palliative treatment after surgery is advocated. Brain stem gliomas account for approximately 10% of all pediatric brain tumours. Cranial nerve signs, ataxia and cerebellar signs with or without symptoms and signs of raised intracranial pressure are classically described symptoms and signs. Radiographic findings and clinical correlates can be used to categorize brain stem tumours into four types: diffuse, focal, exophytic and cervicomedullary. Histologically most brain stem gliomas are fibrillary astrocytomas. Diffuse brain stem gliomas are the most commonly seen tumour in the brain stem. These lesions are malignant high grade fibrillary astrocytomas. Focal tumours of the brain stem are demarcated lesions generally less than 2 cms in size, without associated edema. Most commonly seen in the midbrain or medulla, they form a heterogeneous pathological group, showing indolent growth except when the lesion is a PNET. Dorsally exophytic tumours lie in the fourth ventricle, while cervicomedullary lesions are similar to spinal intramedullary tumours. Expanding lesions are the only lesions amenable for excision while infiltrative and ventral lesions are not.

Neuroimaging of pediatric posterior fossa tumors including review of the literature

Conventional, anatomical MRI is an essential tool for diagnosis and evaluation of location, quality, and extent of posterior fossa tumors, but offers limited information regarding tumor grade and type. Advanced MRI techniques such as diffusion weighted imaging (DWI) and diffusion tensor imaging (DTI) may improve the specific diagnosis of brain tumors in the posterior fossa in children. In this review the conventional neuroimaging findings, as well as the DWI, and DTI characteristics of common pediatric posterior fossa tumors are discussed and summarized.

Radiographically distinct variant of pilocytic astrocytoma: a case series

The imaging findings of pilocytic astrocytomas are classically described as a cyst with an enhancing mural nodule. We report 2 unusual cases of multicystic cerebellar midline masses that were proven to be pilocytic astrocytomas. The uniqueness of the imaging features in these cases may represent an important variant of pilocytic astrocytomas. Recognition of this variant may prevent an unnecessary workup to exclude other etiologies such as parasitic infection (ie, cysticercosis) or cystic metastatic disease.

In pursuit of prognostic factors in children with pilocytic astrocytomas

OBJECTIVE

This study described a 23-year experience in the treatment of children with pilocytic astrocytomas (piloA) with the aim of identifying putative clinical, histopathological, and/or immunohistochemical features that could be related to the outcome of these patients.

METHODS

Clinical data of 31 patients under 18 years of age with piloA were obtained from 1984 to 2006.

RESULTS

The mean age at the time of surgery was 7.8 +/- 4.2 years (1 to 17 years), and the mean follow-up was 5.7 +/- 5.4 years (1 to 20 years). The most common site of tumor formation was the cerebellum (17), followed by brainstem (4), optic chiasmatic hypothalamic region (4), cerebral hemisphere (3), cervical spinal cord (2), and optic nerve (1). Gross total resection (GTR) was achieved in 23 (74.1%), mainly in those with tumors located in the cerebellum and cerebral hemispheres (P = 0.02). The global mortality rate was 6.4%. Nine patients were reoperated. Rosenthal fibers, eosinophilic granular bodies, microvascular proliferation, and lymphocytic infiltration were observed in most cases. The mean Ki-67LI was 4.4 +/- 4.5%. In all cases, Gal-3 expression in tumor cells was observed with variable staining pattern.

CONCLUSIONS

Aside from GTR, no other clinical, histopathological, or immunohistochemical features were found to be related to the prognosis. We postulate that strict follow-up is recommended if piloA is associated with high mitotic activity/Ki67-LI, or if GTR cannot be achieved at surgery. Tumor recurrence or progression of the residual lesion should be strictly observed. In some aspects, childhood piloA remains an enigmatic tumor.

Outcome of children with low-grade cerebellar astrocytoma: long-term complications and quality of life

OBJECTS

To study the long-term outcome of surgically treated low-grade cerebellar astrocytomas in children.

MATERIALS AND METHODS

We followed 31 consecutive patients under 16 years of age who were diagnosed between 1980 and 2005 in a single institution. In 21 of 31 survivors (median follow-up time 7.9 years; range 5.6-27.4 years) who agreed to participate, tumor control, neurological and cognitive complications, and their impact on behavioral and emotional adjustment and health-related quality of life (HRQoL) were comprehensively assessed qualitatively and quantitatively.

RESULTS

Neurological sequelae were found in 43%. However, age-appropriate ability to perform daily life activities was normal in all patients. Remarkably, cognitive deficits leading to significant school problems occurred in 19% and behavioral and emotional adjustment disturbances in 27%. In comparison with healthy controls, the survivors rated their HRQoL similarly or even higher.

CONCLUSION

Childhood low-grade cerebellar astrocytomas have an excellent cure rate by tumor surgery alone. When compared with other pediatric brain tumors, the risk of neurological, cognitive, emotional, and behavioral complications is relatively small. HRQoL is similar to that of healthy controls.