Prevalence of BRAF V600 in primary gliomas: a systematic review

Aims Glioma is a fatal disease that causes significant years of life lost to an individual. Mutations in the driver gene BRAF, such as the V600 alteration, may contribute to gliomagenesis in adults and children through abnormal signaling causing uncontrolled cell proliferation. The use of BRAF-inhibitor drugs including Vemurafenib and Dabrafenib have shown a favorable response in 48% and 50% of melanoma patients with BRAF V600 mutations respectively. BRAF inhibitors and MEK inhibitors have shown efficacy in certain paediatric gliomas in the recurrent setting. Despite the potential benefit of BRAF inhibitors, the prevalence of BRAF V600 within primary gliomas is not fully discovered. Some studies identify the prevalence to be over 50%, while others find the prevalence to be around 1%. We performed a comprehensive systematic review to determine the prevalence of BRAF V600 within the adult and paediatric glioma population in different diagnostic groups. Method A systematic literature search was performed using Ovid MEDLINE and Embase from genesis to the 22nd October 2020. Studies were not restricted by language. Studies were eligible if patients were histologically diagnosed according to WHO guidelines as a primary glioma evaluating the prevalence of BRAF V600 and included ≥ 10 primary glioma patients. The review protocol was registered in PROSPERO (CRD42019127704). Search results were managed using Endnote. Two independent reviewers assessed the eligibility of the publications using Rayyan, conflicts were evaluated by a third reviewer. Included articles were extracted by one reviewer and confirmed by a second reviewer. Risk of bias assessments were conducted using Hoy et al’s risk of bias tool. Results were synthesized using “metaprop” in R. The meta-analysis was carried out in R which produced forest plots. Results Our cohort included 182 studies with a total of 13669 adult and paediatric glioma patients classified diagnostically according to WHO guidelines. Among 48 glioma entities, BRAF V600 was identified most commonly in epithelioid glioblastoma with a prevalence of 69% (95% confidence interval (CI): 45-89%), followed by pleomorphic xanthoastrocytoma with a prevalence of 56% (95% CI: 48-64%), anaplastic pleomorphic xanthoastrocytoma with a prevalence of 38% (95% CI: 23-54%), ganglioglioma with a prevalence of 40% (95% CI: 33-46%), and anaplastic ganglioglioma with a prevalence of 46% (95% CI: 18-76%). Other glioma entities were found to have a prevalence of BRAF V600, these include astroblastoma (24%), desmoplastic infantile astrocytoma (16%), subependymal giant cell astrocytoma (8%), dysembryoplastic neuroepithelial tumour (3%), diffuse astrocytoma (3%), and pilocytic astrocytoma (3%). Conclusion To our knowledge, this is the largest systematic review examining the prevalence of BRAF V600 in adult and paediatric glioma classified according to diagnostic WHO criteria. However, there were some limitations in this review. The sample sizes of some studies were very small, and the method of mutational analysis for BRAF V600 varied between papers. We found BRAF V600 in a significant prevalence of epithelioid glioblastoma, pleomorphic xanthoastrocytoma, anaplastic pleomorphic xanthoastrocytoma, ganglioglioma, and anaplastic ganglioglioma. Of interest, BRAF V600 mutation was found in a lower prevalence of astroblastoma, desmoplastic infantile astrocytoma, subependymal giant cell astrocytoma, dysembryoplastic neuroepithelial tumour, diffuse astrocytoma, and pilocytic astrocytoma. Consideration of assessment of BRAF V600 mutation may enable further treatment options with BRAF and/or MEK inhibitors in these particular diagnostic entities.

Huge Renal Angiomyolipoma in a Child with Tuberous Sclerosis Complex: A Diagnostic and Therapeutic Dilemma

Tuberous Sclerosis Complex (TSC) is a rare neuro-cutaneous disorder that is associated with the development of benign hamartomas including renal angiomyolipoma (RAML). TSC associated RAML are usually asymptomatic, but it carries a life-threatening bleeding risk. We are sharing a case of a 5-year-old girl who was diagnosed to have TSC with associated subependymal giant cell astrocytoma, cardiac rhabdomyoma and autism. She presented with a history of worsening abdominal distension over 3 weeks duration and clinically noted to be pale with a ballotable left flank mass. Ultrasound and CT scan found to have multiple RAML in both kidneys with a huge mass on the left side. The mass represented a huge RAML (8cm) with aneurysmal formation with suspicion of intratumoral bleeding. The option of conservative management with mammalian target of rapamycin inhibitor followed with partial nephrectomy has been questioned with its life-threatening risk of bleeding and inability to do biopsy to rule out the possibility of renal cell carcinoma. Decision for nephrectomy was then made clearer following a MAG-3 scan which revealed only 11% differential function of the left kidney. She underwent a total left nephrectomy uneventfully and intraoperatively noted to have an enlarging lesion as compared to the previous imaging; 15cm in largest diameter. Histopathological finding was consistent with multifocal angiomyolipoma with intratumoral haematoma. Decision for nephrectomy in TSC-associated RAML need to be justified carefully in view of its risk of losing the contralateral kidney following the disease progression which may end up with life-long renal replacement therapy.International Journal of Human and Health Sciences Supplementary Issue-2: 2021 Page: S26

Long Term Outcome and Histologic Findings of a Retinal Astrocytic Hamartoma Treated with Intravitreal Injection of Anti-VEGF: A Case Report

Background. To our knowledge, this is the first report to describe the histologic changes of a retinal astrocytic hamartoma (RAH) in a patient with tuberous sclerosis complex (TSC) treated with antivascular endothelial growth factor (anti-VEGF), as well as the longest anti-VEGF treatment that such a patient has received (3 years). Case Presentation. We present a case of a 20-year-old female with TSC who developed progressive growth of a papillary astrocytic hamartoma that caused significant retinal edema, vitreous hemorrhage, and neovascular glaucoma. The patient was initially treated with 25 intravitreal anti-VEGF injections about every 1-3 months, but eventually developed a blind painful eye from neovascular glaucoma. Histopathologic evaluation of the enucleated globe showed a peculiar difference of the tumor according to its topography, with features reminiscent of pilocytic astrocytoma at the optic nerve head and features reminiscent of subependymal giant cell astrocytoma at the retrolaminar optic nerve. We hypothesize that these changes occurred as a secondary effect of the anti-VEGF treatment. Conclusions. Anti-VEGF agents may decrease the ophthalmologic complications of RAH. We recommend that this treatment should be started early and continued for a protracted time at regular and frequent intervals. Moreover, a combination of therapies might prove to be superior to monotherapy and should therefore be considered in aggressive retinal astrocytic hamartomas.

Lesions at the Foramen of Monro Causing Obstructive Hydrocephalus

The foramen of Monro has also been referred to by the name of interventricular foramen. The structures comprising this foramen are the anterior part of the thalamus, the fornix and the choroid plexus. Vital structures surround the foramen, the damage to which can be catastrophic leading to disability either temporary or permanent. In the literature it has been shown that tumors occurring in the area of interventricular foramen are rare and usually cause hydrocephalus. The operative approach depends upon the location of the tumor which can be either in the lateral or the third ventricle. Various pathologies which can lead to foramen of Monro obstruction and obstructive hydrocephalus include colloid cyst, craniopharyngioma, subependymal giant cell astrocytoma [SEGA], Neurocysticercosis, tuberculous meningitis, pituitary macroadenoma, neurocytoma, ventriculitis, multiseptate hydrocephalus, intraventricular hemorrhage, functionally isolated ventricles, choroid plexus tumors, subependymomas and idiopathic foramen of monro stenosis. In this chapter, we will discuss the various lesions at the level of foramen of Monro causing obstructive hydrocephalus and the management and associated complications of these lesions based on their type, clinical picture and their appearance on imaging.