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Central Nervous System
Published in Pat Price, Karol Sikora, Treatment of Cancer, 2020
Anaplastic astrocytoma (AA) is a diffusely infiltrating, astrocytic tumor typified by increasing cellularity, increasing nuclear size and variation, and the presence of mitoses (growth fraction around 5%–10%). In the WHO classification, tumor necrosis must not be present. Tumors in this category that carry co-deletions on chromosomes 1p and 19q are diagnosed and treated as anaplastic oligodendroglioma (AO). AA is primarily a tumor appearing during middle age. It appears with variable density on CT or signal on MRI. There is usually enhancement with contrast, but this may be diffuse or patchy and is rarely of the classical “ring” type seen in GBM. Unlike LGA, rapid growth in AA is the rule. Treatment must include maximal safe surgery and high-dose radiotherapy as for GBMs, leading to a median survival of 2–5 years. The CATNON Intergroup trial is examining the role of concurrent and/or adjuvant temozolomide in patients with non-1p/19q-deleted anaplastic glioma.49
The nervous system and the eye
Published in C. Simon Herrington, Muir's Textbook of Pathology, 2020
James A.R. Nicoll, William Stewart, Fiona Roberts
Diffuse astrocytoma, IDH-mutant (WHO grade II) occurs most frequently in younger adults and can arise throughout the CNS, but most frequently in the frontal lobes. Radiology studies show an ill-defined, low-density lesion without contrast enhancement. Macroscopically the tumour may be difficult to distinguish from the surrounding brain. It is homogeneous, abnormally firm, may contain cysts, and diffusely infiltrates surrounding brain structures. Histologically, the tumour is composed of cells resembling astrocytes, with molecular studies showing mutation in either the IDH1 or the IDH2 gene. Mitoses, endothelial cell hyperplasia, and necrosis are not present. Median survival is around 11 years, most eventually transforming to a higher grade tumour (anaplastic astrocytoma or glioblastoma). Anaplastic astrocytoma, IDH-mutant (WHO grade III) arises in a similar age group to its lower-grade variant and shows evidence of mitotic figures, but without endothelial hyperplasia or necrosis. Median survival is around 9 years. Variants of diffuse and anaplastic astrocytomas without IDH mutations (IDH-wildtype) are less common than mutant variants and clinically more aggressive.
Astrocytoma
Published in Dongyou Liu, Tumors and Cancers, 2017
Anaplastic astrocytoma is a malignant tumor that represents an intermediate stage in the progression of diffuse astrocytoma to glioblastoma. Commonly found in the cerebrum, and occasionally in the cerebellum, brain stem, and spinal cord, anaplastic astrocytoma grows rapidly and often invades nearby healthy tissue. Macroscopically, the tumor may contain regions of lower grade diffuse astrocytoma (with an ivory white central region and modest blood supply) and higher grade glioblastoma (with a gray-purple region and rich blood supply). Histologically, the tumor displays frequent mitoses (which differs from diffuse astrocytoma), nuclear pleomorphism, and increased cellular density. Molecular determination of the status of the IDH and TP53 genes, facilitates the classification of anaplastic astrocytoma, IDH mutant; anaplastic astrocytoma, IDH wild-type; and anaplastic astrocytoma, NOS [1].
Diagnostic accuracy of diffusion-weighted imaging in differentiating glioma recurrence from posttreatment-related changes: a meta-analysis
Published in Expert Review of Anticancer Therapy, 2022
Xiaoli Du, Qian He, Boli Zhang, Na Li, Xuewen Zeng, Wenbo Li
The five-year survival rate of patients with high-grade glioma, such as glioblastoma, is less than 5%, and that of patients with anaplastic astrocytoma is less than 30% [3]. Presently, the standard treatment for high-grade glioma is surgical resection and postoperative concurrent chemoradiotherapy, supplemented by 6 cycles of temozolomide [4]. Patients receiving postoperative radiotherapy and chemotherapy for glioma may have posttreatment-related changes (pseudoprogression and radiation necrosis) and recurrence. The timing and clinical manifestations of the two are similar. Routine imaging examination shows newly enhanced lesions, which are difficult to distinguish in the early stage [5]. The clinical treatment and prognosis for recurrent glioma and pseudoprogression and radiation necrosis are different. Although secondary surgery is the gold standard to perform a pathological diagnosis, its use is limited because of its invasiveness. Therefore, early application of noninvasive imaging to evaluate postoperative recurrence and pseudoprogression of glioma is critical to select the appropriate treatment and determine patient prognosis.
DNX-2401: an investigational drug for the treatment of recurrent glioblastoma
Published in Expert Opinion on Investigational Drugs, 2019
Brandon Philbrick, David C. Adamson
Glioblastoma and anaplastic astrocytoma have been the target of many clinical trials in recent decades, yet they remain some of the most fatal malignancies. Due to their rapid and devastating effects on the brain, there is a desperate need for better treatments for these tumors. It takes little convincing to see that drug therapies offer the greatest potential for treatment of these tumors. Despite advances in neurosurgical operative techniques like neuronavigation, intra-operative fluorescent biomarkers to visualize the tumor, and functional brain mapping that have assisted in providing more precise tumor resections, these tumors still quickly progress despite >95% resection of the tumor. In these cases, adjuvant chemotherapies have the potential to eliminate the residual tumor and prevent future recurrences. All of the widely used therapies for HGG and rHGG have provided a very modest prolongation of survival – typically by no more than a few months.
Multicentric high grade oligodendroglioma: a rare entity
Published in British Journal of Neurosurgery, 2019
Atul Vats, Amit Amit, Paresh Doshi
Oligodendrogliomas are intrinsic brain tumour which are usually calcified solitary tumours made up of predominantly oligodendrocytes and are usually low grade gliomas (WHO Grade 2). Oligodendroglioma is commonly located in the frontal lobe. When the tumors are of mixed cell origin and contain both astrocytic and oligodendrocytic components, the astrocytic component often progresses and degenerates into anaplastic astrocytoma. This phenomena occurs in about half of oligodendrogliomas. Anaplastic oligodendroglioma (WHO grade III) has high-grade features, such as increased mitotic activity, microvascular proliferation, or necrosis. Multicentric oligodendroglioma is an extremely rare entity. Although a solitary case of multicentric low grade oligodendroglioma has been reported,1 we could not find any reports on high grade multifocal oligodendroglioma on literature search.