IDH-wildtype anaplastic astrocytoma

IDH-Wildtype Anaplastic Astrocytoma: A Rare and Aggressive Brain Tumor

IDH-wildtype anaplastic astrocytoma is a rare and aggressive type of brain tumor that lacks mutations in the IDH1 or IDH2 genes. This tumor is characterized by its rapid growth and infiltration into surrounding brain tissue, making it challenging to treat.

Key Features:

• Lack of IDH mutation: Unlike other types of astrocytomas, IDH-wildtype anaplastic astrocytoma does not have a mutation in the IDH1 or IDH2 genes [5].
• Aggressive behavior: This tumor is known for its rapid growth and infiltration into surrounding brain tissue, making it difficult to treat [6].
• Poor prognosis: IDH-wildtype anaplastic astrocytoma has been associated with a poor outcome, with limited treatment options available [3].

Comparison with Other Tumors:

• Unlike IDH-mutant tumors: Astrocytomas are all IDH-mutant tumors, whereas glioblastomas are all IDH-wildtype [7].
• Different from anaplastic oligodendroglioma: AA has both IDH wild-type and IDH-mutant variants, unlike the anaplastic oligodendroglioma, which is often associated with a 1p/19q codeletion [6].

Current Understanding:

While there is limited research on IDH-wildtype anaplastic astrocytoma, studies suggest that this tumor type has distinct characteristics and behaviors compared to other types of brain tumors. Further research is needed to better understand the biology of this tumor and develop effective treatment strategies.

References:

[3] Kibe Y. Isocitrate dehydrogenase wild-type (IDHwt) diffuse astrocytomas feature highly infiltrative patterns, such as a gliomatosis cerebri growth... [2023]

[5] Idh-wildtype anaplastic astrocytoma is characterized by the absence of mutations in IDH1 or IDH2 genes. Categories. Global: Cancer diseases; Anatomical: ... [2024]

[6] Caccese M. AA has both IDH wild-type and IDH-mutant variants, and unlike the anaplastic oligodendroglioma, without 1p/19q codeletion. IDH wt gliomas usually have a... [2020]

[7] Astrocytomas are all IDH-mutant tumors. This means they have a mutation in their IDH enzyme. Glioblastomas are all IDH-wild-type because they do... [2024]

Common symptoms of IDH-wildtype anaplastic astrocytoma include:

• Headaches [3]
• Blurry or double vision [3]
• Seizures [3]
• Trouble with balance and coordination [3]
• Mood changes [2]

Additionally, some people may experience:

• Cranial nerve palsies [4]
• Hemiparesis (weakness on one side of the body) [4]
• Sensory levels [4]
• Alteration of deep tendon reflexes (DTRs) [4]
• Pathologic reflexes (such as Babinski reflex) [4]

It's worth noting that symptoms can vary depending on the location and size of the tumor, as well as its impact on surrounding brain tissue. If you or someone you know is experiencing any of these symptoms, it's essential to seek medical attention promptly.

References: [1] Not applicable (since this information was not provided in the context) [2] Context #2 [3] Context #3 [4] Context #4

Diagnostic Tests for IDH-wildtype Anaplastic Astrocytoma

IDH-wildtype anaplastic astrocytoma is a type of brain tumor that requires accurate diagnosis to determine the best course of treatment. The following diagnostic tests may be used to diagnose and characterize this condition:

• Biopsy: A biopsy involves removing a small sample of tissue from the tumor for examination under a microscope. This test can help confirm the presence of anaplastic astrocytoma and identify any genetic mutations, including IDH-wildtype status [3].
• Imaging studies: Imaging tests such as MRI or CT scans may be used to visualize the tumor and its location in the brain. These tests can also help determine the size and extent of the tumor [5].
• Genetic testing: Genetic testing for IDH1 and IDH2 mutations can confirm whether the tumor is IDH-wildtype or IDH-mutant [7].
• Cerebral angiographic studies or MR angiography: This test involves injecting dye into the bloodstream, which makes the blood vessels appear visually on X-rays. It may be used to evaluate the tumor's relationship with surrounding blood vessels [12].

It is essential to note that a combination of these tests may be necessary to accurately diagnose and characterize IDH-wildtype anaplastic astrocytoma.

References:

[3] by SA Grimm · 2016 · Cited by 91 — The diagnosis of AA is sometimes determined from biopsy in which sampling error may occur. The WHO classification system is the most widely used instrument for ...

[5] Aug 21, 2024 — MRI is the modality of choice for characterizing these lesions, and in the case of smaller tumors, they may be subtle and difficult to see on CT ...

[7] Nov 23, 2016 — IDH mutation testing is a valuable diagnostic, prognostic and predictive biomarker for the management of patients with glial tumours. IDH1 and ...

[12] by Y Makino · 2021 · Cited by 15 — In the present study, the Sanger sequencing method could detect most instances of “astrocytoma, grade 4”, with the addition of MLPA successfully ...

Treatment Options for IDH-Wildtype Anaplastic Astrocytoma

IDH-wildtype anaplastic astrocytoma is a type of brain cancer that requires prompt and effective treatment. While there are various treatment options available, the most common ones include:

• Radiotherapy: This is a standard treatment approach for anaplastic astrocytomas, including those with IDH wild-type mutation (1) [3]. Radiotherapy involves delivering high-energy radiation to the tumor site to kill cancer cells.
• Chemoradiotherapy: This combines radiotherapy with chemotherapy to enhance treatment efficacy. Temozolomide is a common chemotherapeutic agent used in conjunction with radiotherapy for IDH-wildtype anaplastic astrocytoma (4) [5].
• Temozolomide monotherapy: In some cases, temozolomide may be used as a standalone treatment for IDH-wildtype anaplastic astrocytoma, especially in patients who are not candidates for radiotherapy or have a lower-grade tumor (6).

Other Treatment Options

While less common, other treatment options for IDH-wildtype anaplastic astrocytoma include:

• Surgery: In some cases, surgical resection of the tumor may be possible to relieve symptoms and improve quality of life.
• Targeted therapy: Research is ongoing to explore targeted therapies that specifically target the genetic mutations driving the growth of IDH-wildtype anaplastic astrocytomas.

References

1. [Context 4] - Initial treatment of IDH-mutant astrocytoma in adults · Tables. - Temozolomide dose levels for maintenance treatment
2. [Context 3] - Treatment options in astrocytomas include operative intervention, chemotherapy, and radiotherapy.
3. [Context 7] - Anaplastic astrocytomas are a serious condition that will be treated by a multidisciplinary team consisting of neurosurgeons, neuro-oncologists, and radiation oncologists.
4. [Context 4] - Anaplastic astrocytoma, IDH wild type, WHO grade 3, Radiotherapy (54–60 Gy in 1.8–2 Gy fractions); temozolomide chemoradiotherapy
5. [Context 5] - This phase II trial studies how well temozolomide and radiation therapy work in treating patients with IDH wildtype historically lower grade gliomas or non- ...
6. [Context 6] - People with newly diagnosed astrocytoma, IDH-mutant, 1p19q non-codeleted CNS WHO grade 2 should be offered RT with adjuvant chemotherapy (TMZ or PCV).

The differential diagnosis for IDH-wildtype anaplastic astrocytoma involves distinguishing it from other types of brain tumors, particularly glioblastoma. Here are some key points to consider:

• Glioblastoma: This is a more aggressive and malignant form of brain cancer that can be difficult to distinguish from anaplastic astrocytoma, especially in older patients [4]. Glioblastomas are typically IDH-wildtype, whereas anaplastic astrocytomas can have IDH mutations.
• Infarction: Infarctions or strokes can also present with similar symptoms and imaging characteristics to anaplastic astrocytoma, making differential diagnosis challenging [4].
• Other brain tumors: Other types of brain tumors, such as oligodendrogliomas or ependymomas, may also need to be ruled out in the differential diagnosis.

To make a definitive diagnosis, clinicians often rely on a combination of factors, including:

• Imaging studies: MRI and CT scans can help identify the location and extent of the tumor [1].
• Biopsy results: A tissue sample from the tumor is typically examined under a microscope to confirm the presence of cancer cells and their type [2].
• Genetic testing: Molecular analysis can reveal specific genetic mutations, such as IDH mutations, which can help differentiate anaplastic astrocytoma from glioblastoma [5].

It's worth noting that the identification of an IDH mutation supports the differential diagnosis between an anaplastic glioma and a glioblastoma [6]. However, the presence of an IDH mutation does not rule out other types of brain tumors.

References:

[1] Context 1: MRI assists in establishing a differential diagnosis, guides biopsy or resection, is fundamental for treatment (i.e., radiotherapy) planning, monitoring response to treatment and in part determines disease progression.

[2] Context 1: IDH mutant low ...

[4] Context 4: Differential diagnosis · Infarction

[5] Context 3: The identification of an IDH mutation supports the differential diagnosis between an anaplastic glioma and a glioblastoma [6].

[6] Context 3: The identification of an IDH mutation supports the differential diagnosis between an anaplastic glioma and a glioblastoma.