Intratumoral histological and molecular heterogeneity in an adult diffuse glioma.

Adult-type diffuse gliomas are the most prevalent type of malignant adult brain tumors. Intratumoral heterogeneity can hinder accurate diagnosis and subsequent treatment. This case report documents a tumor with intratumoral heterogeneity, both histologically and by methylation analysis, located within the left cerebral hemisphere of a 29-year-old female. She presented after a witnessed generalized tonic clonic seizure at home. Two years prior she had a witnessed seizure; however, no brain imaging was done at the time. Magnetic resonance imaging (MRI), on this admission, showed a mass lesion in the left frontal operculum with poorly identified margins and right-sided midline shift. Sampling from the left temporal lobe showed an IDH-mutant, ATRX-mutant astrocytoma, which appeared grade 4 in the enhancing anterior portion and grade 2 in the left temporal lobe. Methylation analysis confirmed this heterogeneity. In summary, this is an excellent example of tumor heterogeneity both histologically and by molecular analysis. It is probable, given the clinical history of presentation 2 years prior, that this tumor originated as a low-grade glioma and subsequently evolved.

Brain biopsy in neurological disease of unknown etiology: A single-center 12-year retrospective analysis.

There are no international guidelines for brain biopsy in neurological disease of unknown etiology, yet most practicing neurologists will encounter difficult cases in which biopsy is considered. This patient cohort is heterogenous, and it is unclear in which circumstances biopsy is most useful. We performed an audit of brain biopsies reviewed in our neuropathology department from 2010 to 2021. Of 9,488 biopsies, 331 biopsies undertaken for an undiagnosed neurological disease were identified. Where documented, the commonest symptoms were hemorrhage, encephalopathy, and dementia. 29% of biopsies were non-diagnostic. The most common clinically relevant findings on biopsy were infection, cerebral amyloid angiopathy with or without angiitis, and demyelination. Rarer conditions included CNS vasculitis, non-infectious encephalitis, and Creutzfeldt Jakob Disease. We highlight the value of brain biopsy in the workup of cryptogenic neurological disease despite recent advances in less invasive diagnostics.

Establishing a committee for antemortem reviews of suspect Creutzfeldt-Jakob disease cases in Ireland.

BACKGROUND: Creutzfeldt-Jakob disease (CJD) is a rapidly progressive, neurodegenerative disease. In Ireland, clinical diagnostics and laboratory testing remain the responsibility of the managing clinician and the Neuropathology Department at the Beaumont Hospital, respectively. Centralized review of individual cases is not undertaken. AIMS: To determine how diagnostic processes for CJD could be improved in Ireland and to outline the structure and referral process for a new CJD review panel at the Beaumont Hospital. METHODS: We surveyed Irish neurologists' experiences on the management of CJD in Ireland. We measured turnaround times (TAT) for CSF samples referred for diagnostic CJD testing. Finally, we retrospectively reviewed imaging of autopsy-proven CJD cases to compare with initial reports. RESULTS: Ninety-three percent of neurologists supported a national central review of suspect CJD cases. A second clinical opinion was considered to be of likely benefit by 79%. Additionally, 93% reported that a centralized review of neuroradiology would be useful. All respondents felt that expediting turnaround of CSF analysis would be of benefit. The average TAT for CSF testing was 35.4 days. In retrospective review of imaging, all patients demonstrated MRI findings consistent with CJD. However, in only one of these cases were the initial pre-autopsy radiological findings reported as being consistent with CJD. CONCLUSIONS: These findings support the need for improvements to the Irish National CJD Surveillance Unit to maximize antemortem diagnostic accuracy. On foot of this, a clinical CJD Multidisciplinary Team (CJD MDT) has been established to provide a second opinion on (i) the patient's clinical history, (ii) neuroradiology and (iii) and neurophysiology reports (where available).

Impact of the 2016 World Health Organization Classification of Tumours of the Central Nervous System: an Irish experience.

The 2016 World Health Organization Classification of Tumours of the Central Nervous System Tumours represents the most significant update to neuro-oncological tumour classification to date, compared with previous updates. This update reflects the substantial advances in molecular and genetic understanding of both adult and childhood brain tumours which have occurred in recent years. These advances have meant that an increasing array of molecular tests are required to definitively classify a tumour, allowing for a more precise integrated pathological diagnosis, but at the expense of a more challenging pathology workup. We review the changes incorporated into the 2016 classification and describe the impact of these changes in an Irish neuropathology laboratory.