A Cerebellar High-Grade Neuroepithelial Tumour with BCOR Alteration in a five-year-old Child: A case report

ABSTRACT: New groups of high-grade neuroepithelial tumours (HGNET) have emerged from the reclassification of central nervous system (CNS) embryonal tumours that have recognised CNS HGNET with BCOR alteration (CNS HGNET-BCOR). We report a two-year, nine-month-old Omani boy who presented to the Royal Hospital, Muscat, Oman, in 2015 with subacute head tilting and neck pain. A well-defined cerebellar lesion was found and he was treated with standard chemoradiotherapy. After a relapse at the age of five years, molecular testing revealed a BCOR alteration. He was treated with further surgery and high-dose chemotherapy; unfortunately, he relapsed and died three years after he was diagnosed.Keywords: Neuroepithelial Tumor; Glioblastoma; Human BCOR Protein; Embryonal Tumors; Case Report; Oman.

Invasive EEG in Tumoural Epilepsy

Long-term epilepsy-associated tumours (LEATs) are usually dysembryoplastic neuroepithelial tumours (DNTs) and gangliogliomas. Both usually show childhood-onset intractable partial epilepsy, concordant focal EEG abnormalities, and predominant temporal location. Imaging showing typical pseudocystic pattern is suggestive of DNT. Gangliogliomas are characterized by association of a true cyst and nodular contrast enhancement. However, less typical patterns may also be seen, rendering differentiation between the two difficult. Stereo-EEG has demonstrated intrinsic epileptogenicity of both, the typical interictal pattern consisting of repetitive spikes on depressed background activity. Ictal onset discharges arise from tumour in all cases, spreading to peritumoural and secondarily distant areas. Intratumoural stimulations elicit seizures similar to spontaneous seizures. Hippocampus is involved early in most temporal tumours. Epileptogenic zone organization differs according to DNT subtypes, co-localized with tumour in simple and complex forms, and more extended in non-specific forms. In gangliogliomas, the epileptogenic zone is similar to that observed in non-specific DNTs.

Neurological tumours

Neurological tumours are categorized by the WHO as follows: neuroepithelial tumours (gliomas, oligodendrogliomas, ependymomas, pineal parenchymal tumours, medulloblastoma, neuronal and neuroglial tumours); cranial and paraspinal nerve tumours (schwannoma, neurofibromas); meningeal tumours (meningiomas); lymphomas; germ cell tumours (germinoma, teratoma); sellar region tumours (cranipharyngioma); and metastases. The tumours are classified according to grade. The WHO histological grading scheme used for astrocytomas is based on mitoses, nuclear pleomorphism, necrosis, and endothelial proliferation. WHO Grade I and Grade II tumours are low-grade tumours, and WHO Grade III and Grade IV tumours are high-grade tumours.