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Oligodendroglioma

Updated : April 18, 2024





Background

Oligodendroglioma (OG) is a form of diffusely infiltrating glioma that accounts for about 5% of primary intracranial tumours. They frequently affect the cortical grey matter and are particularly prevalent in the frontal lobes. Historically, the tumor’s histological appearance determined the diagnosis of OG.

In 2016, the classification criteria for CNS malignancies was modified to include phenotypic and genotypic investigations. In general, OGs are low-grade neoplasms with a positive treatment response compared to other gliomas.

Their growth is comparatively slow. Grade III anaplastic OG is a malignant type of the tumour that portends a poorer prognosis and may arise de novo or as a degeneration of a lower grade OG.

Epidemiology

Following glioblastoma and diffuse astrocytoma, OGs are the third most frequent primary brain tumour, with a frequency of 0.2 per 100,000 people. OGs account for roughly 5% of primary CNS tumours.

One study found a male-to-female ratio as low as 0.92, indicating a minor male predominance ranging from 1.1 to 2 males for every female. OGs have a modest bimodal distribution, but are primarily adult neoplasms with an incidence peak in the 30s and 40s and a smaller incidence peak in children aged 6 to 12 years.

Oligendrogliomas display have different molecular markers in children and in adults, so researchers are unsure if both of these are from the same neoplasm.

Anatomy

Pathophysiology

OGs are located largely in the white matter of the cerebral hemisphere (80 to 90 percent supratentorial), most frequently in the frontal lobes, however involvement of the temporal and parietal lobes is not uncommon.

The tumour is predominantly located in the cortical-subcortical region, with diffuse infiltration of the surrounding white matter. OG has also been identified as intraventricular or subependymal, albeit this is uncommon.

Etiology

In 1929, oligodendroglioma was named the same because when Bailey and Bucy viewed these cells under the microscope, and observed their close resemblance to oligodendrocytes. However, evidence suggesting they originate from adult oligodendrocytes is inconclusive.

Tumors appear to originate from neuroprogenitor cells with glial precursors that differentiate into oligodendroglial-type cells lacking the myelinating capacity of oligodendrocytes. The shared driver isocitrate dehydrogenase mutation between diverse diffuse glioma subtypes further supports this notion.

Genetics

Prognostic Factors

Low-grade Oligodendrogliomas with 1p/19q deletion and IDHmt present a better prognosis than astrocytomas lacking these genetic markers. The median survival duration for OGs is 10 to 12 years. Tumors can be progression-free for 51%-83% of patients for 5 years.

Younger patients, which don’t have additional comorbidities, and had most of the tumor removed during surgery fare better. With higher-grade anaplastic OG, overall and 5-year survival rates decrease, with a median survival time of 3.5 years for WHO Grade III tumours.

Clinical History

Physical Examination

Age group

Associated comorbidity

Associated activity

Acuity of presentation

Differential Diagnoses

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

Medication

Media Gallary

References

https://www.ncbi.nlm.nih.gov/books/NBK559184/

Oligodendroglioma

Updated : April 18, 2024




Oligodendroglioma (OG) is a form of diffusely infiltrating glioma that accounts for about 5% of primary intracranial tumours. They frequently affect the cortical grey matter and are particularly prevalent in the frontal lobes. Historically, the tumor’s histological appearance determined the diagnosis of OG.

In 2016, the classification criteria for CNS malignancies was modified to include phenotypic and genotypic investigations. In general, OGs are low-grade neoplasms with a positive treatment response compared to other gliomas.

Their growth is comparatively slow. Grade III anaplastic OG is a malignant type of the tumour that portends a poorer prognosis and may arise de novo or as a degeneration of a lower grade OG.

Following glioblastoma and diffuse astrocytoma, OGs are the third most frequent primary brain tumour, with a frequency of 0.2 per 100,000 people. OGs account for roughly 5% of primary CNS tumours.

One study found a male-to-female ratio as low as 0.92, indicating a minor male predominance ranging from 1.1 to 2 males for every female. OGs have a modest bimodal distribution, but are primarily adult neoplasms with an incidence peak in the 30s and 40s and a smaller incidence peak in children aged 6 to 12 years.

Oligendrogliomas display have different molecular markers in children and in adults, so researchers are unsure if both of these are from the same neoplasm.

OGs are located largely in the white matter of the cerebral hemisphere (80 to 90 percent supratentorial), most frequently in the frontal lobes, however involvement of the temporal and parietal lobes is not uncommon.

The tumour is predominantly located in the cortical-subcortical region, with diffuse infiltration of the surrounding white matter. OG has also been identified as intraventricular or subependymal, albeit this is uncommon.

In 1929, oligodendroglioma was named the same because when Bailey and Bucy viewed these cells under the microscope, and observed their close resemblance to oligodendrocytes. However, evidence suggesting they originate from adult oligodendrocytes is inconclusive.

Tumors appear to originate from neuroprogenitor cells with glial precursors that differentiate into oligodendroglial-type cells lacking the myelinating capacity of oligodendrocytes. The shared driver isocitrate dehydrogenase mutation between diverse diffuse glioma subtypes further supports this notion.

Low-grade Oligodendrogliomas with 1p/19q deletion and IDHmt present a better prognosis than astrocytomas lacking these genetic markers. The median survival duration for OGs is 10 to 12 years. Tumors can be progression-free for 51%-83% of patients for 5 years.

Younger patients, which don’t have additional comorbidities, and had most of the tumor removed during surgery fare better. With higher-grade anaplastic OG, overall and 5-year survival rates decrease, with a median survival time of 3.5 years for WHO Grade III tumours.

https://www.ncbi.nlm.nih.gov/books/NBK559184/