PAX6 is frequently expressed in ependymal tumours and associated with prognostic relevant subgroups

AimsAn ependymoma shows divergent morphological and molecular features depending on their location. The paired box 6 (PAX6) transcription factor is a putative tumour suppressor and drives cancer cells towards a stem cell-like state. A transcriptome study reported high PAX6 expression in ependymal tumours, but data on protein expression are lacking.MethodsWe, therefore, analysed PAX6 expression by immunohistochemistry in 172 ependymoma samples and correlated its expression to histology, WHO grade, anatomical location and molecular subgroups.ResultsMean PAX6 nuclear expression in ependymoma was 27.5% (95% CI 23.3 to 31.7). PAX6 expression in subependymoma (mean: 5%) was significantly lower compared with myxopapillary (30%), WHO grade II (26%) and anaplastic ependymoma (35%). Supratentorial ependymomas also displayed significant lower PAX6 levels (15%) compared with spinal cord tumours (30%). Expression levels in YAP1-fused ependymoma (41%) were higher compared with REL-associated protein (RELA)-fusion positive tumours (17%), while PAX6 expression was similar in posterior fossa group A (33%) and B (29%) ependymomas. Kaplan-Meier analysis in RELA-fusion positive ependymomas and posterior fossa group B showed a significant better outcome for PAX6 at or above the cut-off of 19.45% compared with tumours with PAX6 below the cut-off.ConclusionsWe demonstrate that PAX6 is frequently expressed in human ependymal tumours and immunohistochemistry may be helpful in determining prognostic relevant subgroups.

Diseases of the spinal cord

The spinal cord is subject to numerous pathological processes which may be intrinsic (intramedullary) and/or extrinsic (extramedullary) to the cord. Many diseases can affect the spinal cord. Those of particular note include spondylotic myelopathy, multiple sclerosis, transverse myelitis, subacute combined degeneration of the cord, genetic and vascular disorders, syringomyelia, injury/trauma, motor neuron disease, and cancer—the most common spinal cord tumours are metastasis, astrocytoma, ependymoma, lymphoma. Specific medical and surgical treatments are determined by the particular cause of myelopathy. These may arrest progression, but function that has been lost may not recover fully. Prognosis of acute cord compression is directly related to the time delay between symptom onset and relief of compression. Chronic disability as a consequence of spinal cord disease requires intensive neurorehabilitation.

Central nervous system tumours

Chapter 17 discusses central nervous system tumours, including principles, planning volumes, dose distribution, high- and low-grade glioma, ependymoma, medulloblastoma, germ cell tumours , vestibular (acoustic) schwannoma, pituitary tumours (including craniopharyngioma), meningioma, and primary spinal cord tumours.

TM1-6 Intramedullary spinal cord tumours – a single centre 10 year retrospective review

ObjectivesTo identify clinically relevant predictors of progression free survival by retrospectively analysing the anatomical location, pre- and post-operative function and histology in intramedullary spinal cord tumours from a single neurosurgical centre over 10 years.DesignRetrospective review.Methods49 patients were identified from a surgical database. Variables collected included pre-and post-operative Frankel Grade and Modified McCormick Scale assessments, tumour histology, extent of resection and length of follow up. Chi-Squared, Kaplan-Mier Survival and Mann-Whitney U-Tests were completed.ResultsThere was a statistically significant relationship between identification of the tumour plane and extent of resection (p<0.01), along with the extent of resection and recurrence (p<0.01). Compared to the other histological subtypes, ependymoma’s demonstrated a significantly greater extent of resection (p=0.02). There was a significant relationship between the grade of tumour and progression free survival (p<0.01). We did not find a significant relationship between pre- and post-operative neurological function and survival.ConclusionsTumour plane and the extent of tumour resection are significant determinants of progression free survival. Ependymoma, whilst being the commonest histology in our series were also the most resectable. Whilst complete resection reduces the rate of recurrence, tumour grade is the most important predictor of outcome.

Spectrum of Central Nervous System Tumours in a Tertiary Hospital of Bangladesh

Background: Tumour registry data on intracranial and intraspinal tumours from a newly set up tertiary hospital of Bangladesh is presented here to provide substantial information about the current trends. Materials & methods: Hospital records of patients admitted under the neurosurgery service between January 2016 upto December 2017 were evaluated. Causes with a principal diagnosis of brain and spinal cord tumours were identified. Diagnosis with WHO grading and the histological subtypes are recorded. Results: 86 cases of various tumours were retrieved out of total 98 neurosurgical cases. 70 of these tumours were of intracranial origin and 16 of intraspinal origin. Male to female ratio was approximately 1.28:1. The mean age of the patients was 45.9 years (range 3-75 years). Paediatric and adult patients accounted for 12.6% and 87.4% respectively. Most of the tumours were found in the 6th decade. Paediatric intracranial tumours were predominately by medulloblastoma while adult population showed highest incidence of astrocytic tumours. Some rare entities were also encountered such as intracranial germinoma, Diffuse large B cell lymphoma (DLBCL) and squamous cell carcinoma in a pre-existing intracranial epidermoid cyst. Conclusions: Distribution of CNS tumour among this population gives a glimpse of the prevalence rate of such tumours in our community. This data can be linked to other national and international tumour registry for improved therapeutics and research. J MEDICINE JUL 2019; 20 (1) : 34-37