Anaplastic oligodendroglioma is a neuroepithelial

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

which is believed to originate from oligodendrocytes, a cell type of the

glia Glia, also called glial cells (gliocytes) or neuroglia, are non-neuronal cells in the central nervous system (the brain and the spinal cord) and in the peripheral nervous system that do not produce electrical impulses. The neuroglia make up ...

. In the

World Health Organization (WHO) The World Health Organization (WHO) is a specialized agency of the United Nations which coordinates responses to international public health issues and emergencies. It is headquartered in Geneva, Switzerland, and has 6 regional offices and 15 ...

classification of brain tumors, anaplastic

oligodendroglioma Oligodendrogliomas are a type of glioma that are believed to originate from the oligodendrocytes of the brain or from a oligodendrocyte progenitor cell, glial precursor cell. They occur primarily in adults (9.4% of all primary brain and central ne ...

s are classified as grade III. In the course of the disease, it can degenerate into highly

malignant Malignancy () is the tendency of a medical condition to become progressively worse; the term is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous benign tumor, ''benign'' tumor in that a malig ...

oligodendroglioma, grade IV. The vast majority of oligodendrogliomas occur sporadically, without a confirmed cause and without

inheritance Inheritance is the practice of receiving private property, titles, debts, entitlements, privileges, rights, and obligations upon the death of an individual. The rules of inheritance differ among societies and have changed over time. Offi ...

within a family.

Symptoms

Symptoms of anaplastic oligodendroglioma may include: *

Seizure A seizure is a sudden, brief disruption of brain activity caused by abnormal, excessive, or synchronous neuronal firing. Depending on the regions of the brain involved, seizures can lead to changes in movement, sensation, behavior, awareness, o ...

Headache A headache, also known as cephalalgia, is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of Depression (mood), depression in those with severe ...

* Weakness on one side of the body * Language difficulties * Behavior and personality changes * Balance and movement problems * Memory problems.

Pathogenesis

The (

) anaplastic oligodendroglioma belongs to the group of

diffuse Diffusion is the net movement of anything (for example, atoms, ions, molecules, energy) generally from a region of higher concentration to a region of lower concentration. Diffusion is driven by a gradient in Gibbs free energy or chemical p ...

glioma A glioma is a type of primary tumor that starts in the glial cells of the brain or spinal cord. They are malignant but some are extremely slow to develop. Gliomas comprise about 30% of all brain and central nervous system tumors and 80% of ...

and arises in the

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...

(

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

and

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue that extends from the medulla oblongata in the lower brainstem to the lumbar region of the vertebral column (backbone) of vertebrate animals. The center of the spinal c ...

) from precursor

stem cell In multicellular organisms, stem cells are undifferentiated or partially differentiated cells that can change into various types of cells and proliferate indefinitely to produce more of the same stem cell. They are the earliest type of cell ...

s of the

oligodendrocyte Oligodendrocytes (), also known as oligodendroglia, are a type of neuroglia whose main function is to provide the myelin sheath to neuronal axons in the central nervous system (CNS). Myelination gives metabolic support to, and insulates the axons ...

s. This tumor occurs primarily in middle adulthood with a frequency peak in the 4th and 5th decade of life.

Diagnosis

The most important

diagnostic Diagnosis (: diagnoses) is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in a lot of different academic discipline, disciplines, with variations in the use of logic, analytics, and experience, to determine " ...

procedure is

magnetic resonance imaging Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and ...

(MRI). Occasionally, outside of routine diagnostics, the

metabolism Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the co ...

in the tissue is shown using

positron emission tomography Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, r ...

(PET). The diagnosis is confirmed by a fine tissue examination following an operation. Anaplastic oligodendrogliomas often show a loss of genetic material. About 50 to 70% of WHO grade III anaplastic oligodendrogliomas have combined

allele An allele is a variant of the sequence of nucleotides at a particular location, or Locus (genetics), locus, on a DNA molecule. Alleles can differ at a single position through Single-nucleotide polymorphism, single nucleotide polymorphisms (SNP), ...

losses on the short arm of

chromosome A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...

1 (1p) and the long arm of

19 (19q). This change is mostly referred to as "1p / 19q Co Deletion". It can be seen as favorable for the patient and makes a response to

radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or a material medium. This includes: * ''electromagnetic radiation'' consisting of photons, such as radio waves, microwaves, infr ...

chemotherapy Chemotherapy (often abbreviated chemo, sometimes CTX and CTx) is the type of cancer treatment that uses one or more anti-cancer drugs (list of chemotherapeutic agents, chemotherapeutic agents or alkylating agents) in a standard chemotherapy re ...

more likely. The designation of grade III oligodendroglioma (high grade) generally subsumes the previous diagnoses of anaplastic or malignant oligodendroglioma. Anaplastic oligodendroglioma (1).jpg, Histopathological image of anaplastic oligodendroglioma in cerebrum. Hematoxylin & eosin stain. Anaplastic oligodendroglioma (3).jpg, Zooming, note the irregular cell- and nucleus-shapes. File:IDH1 R132H in anaplastic ologodendroglioma.jpg, IDH1 R132H in anaplastic oligodendroglioma

Treatment

Surgery can help reduce symptoms caused by the tumor. As complete as possible removal of the tumor visible on the MRI is preferred, provided the location of the tumor allows this. Since typically the cells of an anaplastic oligodendroglioma have already migrated into the surrounding healthy brain tissue at the time of diagnosis, a complete surgical removal of all tumor cells is not possible. The "1p / 19q Codeletion" marker plays an increasingly important role in the selection of therapy and therapy combinations. Because this tumor is an "indolent condition" (a slowly progressive medical condition associated with little or no pain) and the potential

morbidity A disease is a particular abnormal condition that adversely affects the structure or function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical conditions that are asso ...

associated with

neurosurgery Neurosurgery or neurological surgery, known in common parlance as brain surgery, is the specialty (medicine), medical specialty that focuses on the surgical treatment or rehabilitation of disorders which affect any portion of the nervous system ...

and

radiation therapy Radiation therapy or radiotherapy (RT, RTx, or XRT) is a therapy, treatment using ionizing radiation, generally provided as part of treatment of cancer, cancer therapy to either kill or control the growth of malignancy, malignant cell (biology), ...

, most neuro-oncologists will initially pursue a course of

watchful waiting Watchful waiting (also watch and wait or WAW) is an approach to a medical problem in which time is allowed to pass before medical intervention or therapy is used. During this time, repeated testing may be performed. Related terms include ''expe ...

and treat patients symptomatically. Symptomatic treatment often includes the use of

anticonvulsants Anticonvulsants (also known as antiepileptic drugs, antiseizure drugs, or anti-seizure medications (ASM)) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also used in the treatment ...

for seizures and

steroids A steroid is an organic compound with four fused rings (designated A, B, C, and D) arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter mem ...

for brain swelling. For further treatment, radiation or chemotherapy with temozolomide or a chemotherapy with Procarbazine, CCNU and

Vincristine Vincristine, also known as leurocristine and sold under the brand name Oncovin among others, is a chemotherapy medication used to treat a number of types of cancer. This includes acute lymphocytic leukemia, acute myeloid leukemia, Hodgkin lym ...

(PCV) has been shown to be effective and was the most commonly used chemotherapy regimen used for treating anaplastic oligodendrogliomas.

Prognosis

5–Year relative survival rate: Age 20–44, 76%. Age 45–54, 67%. Age 55–64, 45%. Procarbazine, lomustine and vincristine have been used since May 1975. For 48 years, new therapeutic options have been regularly tested as part of therapy studies to improve the treatment of anaplastic oligodendroglioma.

Research

, a definitive cure is not possible with anaplastic oligodendrogliomas of WHO grade III. A retrospective study on 1054 patients with anaplastic oligodendroglioma, presented during the 2009 ASCO Annual Meeting, suggests that PCV therapy may be effective. Median time to progression for patients with 1p19q co-deletion was longer following PCV alone (7.6 years) than with temozolomide alone (3.3 years); median overall survival was also longer with PCV treatment versus temozolomide treatment (not reached, vs. 7.1 years). A recent long-term study does affirm that radiation combined with adjuvant chemotherapy is significantly more efficacious for anaplastic oligodendroglioma patients with 1p 19q co-deleted tumors and has become the new standard of care. It is possible that radiotherapy may prolong the overall time to progression for non-deleted tumors. If the tumor mass compresses adjacent brain structures, a

neurosurgeon Neurosurgery or neurological surgery, known in common parlance as brain surgery, is the medical specialty that focuses on the surgical treatment or rehabilitation of disorders which affect any portion of the nervous system including the brain, ...

will typically remove as much of the tumor as he or she can without damaging other critical, healthy brain structures. Recent studies suggest that radiation does not improve overall survival (even when age, clinical data, histological grading, and type of surgery are considered).

Literature

* Weller M, van den Bent M, Preusser M, Le Rhun E, Tonn JC, Minniti G, Bendszus M, Balana C, Chinot O, Dirven L, French P, Hegi ME, A. S. Jakola, M. Platten, P. Roth, R. Rudà, S. Short, M. Smits, M. J. Taphoorn, A. von Deimling, M. Westphal, R. Soffietti, G. Reifenberger, W. Wick: ''EANO guidelines on the diagnosis and treatment of diffuse gliomas of adulthood.'' In: ''Nature reviews. Clinical oncology.'' Volume 18, Number 3, 03 2021, pp. 170-186, , PMID 33293629, (Review).

References

External links

{{Nervous tissue tumors Brain tumor Cancer Types of cancer Neurology