obsolete central nervous system adult tumor

Obsolete Central Nervous System Adult Tumors

The classification of tumors of the central nervous system (CNS) has undergone significant changes over the years, leading to the reclassification of certain tumor types as obsolete. According to recent updates [1], two such tumor types that have been reclassified are:

• Oligoastrocytoma: This type of tumor was previously considered a distinct entity but is now classified under other categories.
• Diffuse Astrocytoma Isocitrate Dehydrogenase (IDH)-wildtype: This tumor type has been reclassified due to advances in genetic understanding and diagnostic techniques.

These changes reflect the evolving nature of cancer classification and diagnosis, as new research and technologies become available. The updated classification systems aim to provide more accurate and informative diagnoses for patients [3].

Key Changes

The reclassification of these tumor types is significant, as it affects how they are diagnosed and treated. The updated classification system takes into account both histologic features and genetic alterations, providing a more comprehensive understanding of CNS neoplasms [13].

Implications

These changes have important implications for radiologists, pathologists, and clinicians who diagnose and manage CNS tumors. Staying current with the latest classification systems and diagnostic markers is essential to provide optimal patient care [15].

References:

[1] Context result 11: "classification of tumors of the central nervous system (CNS) released in November 2021 includes numerous ... Conversely, obsolete tumor types (eg, oligoastrocytoma and diffuse astrocytoma isocitrate dehy-drogenase–wildtype) have been reclassified in ways that..."

[3] Context result 13: "Classification of Tumors of the Central Nervous System introduced a paradigm shift in the diagnosis of CNS neoplasms. For the first time, both histologic features and genetic alterations were incorporated into the diagnostic framework, classifying and grading brain tumors."

[15] Context result 15: "SUMMARY: Neuroradiologists play a key role in brain tumor diagnosis and management. Staying current with the latest classification systems and diagnostic markers is important to provide optimal patient care."

Obsolescence in Central Nervous System Tumors

While modern medical advancements have led to a better understanding and treatment of central nervous system (CNS) tumors, it's essential to note that the signs and symptoms associated with these conditions may vary depending on their type, location, size, and growth rate.

Historical Context

In the past, CNS tumors were often diagnosed at an advanced stage, making treatment more challenging. The symptoms of a brain tumor, for instance, might have included:

• Severe, persistent headaches [3]
• Weakness or somatosensory loss in specific areas of the body
• Visual disturbances, such as blurred vision or double vision [7]
• Altered mental status, including changes in concentration, memory, attention, or alertness [5]
• Nausea and vomiting, especially early in the morning [5]

Symptoms of Obsolete CNS Tumors

In the past, symptoms of obsolete CNS tumors might have included:

• Focal or generalized seizures (fits) [3]
• Aphasia (difficulty speaking or understanding language)
• Headaches combined with increased intracranial pressure
• Altered mental status, including mood disturbances, psychoses, impulse control disorders, and sleeping alterations [6]

Paraneoplastic Neurologic Syndromes

In some cases, CNS tumors might have triggered paraneoplastic neurologic syndromes (PNSs), which are rare but serious conditions that occur when the immune system mistakenly attacks healthy nerve cells. PNS symptoms can include:

• Muscle weakness or paralysis
• Sensory loss or numbness
• Difficulty with coordination and balance
• Cognitive impairment

Diagnosis and Treatment

While these symptoms might have been present in the past, it's essential to note that modern medical practices have improved significantly. Diagnosis is now often made through imaging studies (e.g., MRI or CT scans), and treatment options include surgery, radiosurgery, radiation therapy, chemotherapy, surveillance, and supportive care.

References:

[1] DN Louis et al. (2021) - The 2021 fifth edition introduces major changes that advance the role of molecular diagnostics in CNS tumor classification. [3] T Schneider et al. (2010) - Typical symptoms and signs of CNS tumors. [5] A La Salvia et al. (2021) - Psychiatric symptoms reported in patients with CNS tumors. [6] F Graus et al. (2021) - Paraneoplastic neurologic syndromes (PNSs). [7] May 15, 2020 - Troublesome signs of CNS tumors.

Note: The information provided is based on the context and search results, which may not reflect current medical practices or knowledge.

Based on the provided context, it appears that there are several diagnostic tests and methods used to diagnose central nervous system (CNS) tumors in adults. However, some of these tests may be considered obsolete or outdated.

Obsolete Diagnostic Tests:

• 1p/19q testing: This test was previously used to diagnose certain types of CNS tumors, such as oligodendrogliomas. However, with the advancement of diagnostic molecular testing, this test is no longer necessary for making a diagnosis (13).
• Immunohistochemical analyses: While still useful in some cases, immunohistochemical analyses may not be sufficient on their own to make a definitive diagnosis of certain CNS tumors, such as IDH-mutant oligodendrogliomas (13).

Current Diagnostic Methods:

• Molecular genetic testing: This is now the preferred method for diagnosing CNS tumors, as it provides more accurate and specific results. The World Health Organization (WHO) classification of CNS tumors has been revised to reflect this change (3).
• Advanced diagnostic molecular testing: This includes various tests such as next-generation sequencing, fluorescence in situ hybridization, and others that can provide detailed information about the genetic makeup of a tumor (15).

Other Relevant Information:

• Brain biopsy: While not specifically mentioned as an obsolete test, brain biopsies are still used to diagnose CNS tumors, especially when imaging tests are inconclusive or surgery is too risky (1).
• Imaging studies: CT and MRI scans are commonly used to diagnose CNS tumors, but these tests may need to be repeated after treatment to monitor for recurrence (8).

In summary, while some diagnostic tests and methods may be considered obsolete, current practices in diagnosing CNS tumors in adults rely heavily on advanced molecular genetic testing and other cutting-edge techniques.

Based on the provided context, it appears that there are various treatment options available for adult central nervous system (CNS) tumors.

Historical Treatment Options

• Valproic acid was once used as an antiepileptic drug in patients with brain tumors [1].
• Mebendazole might have been considered a potential candidate for treating brain tumors due to its efficacy, both as monotherapy and in combination [4].

Current Treatment Approaches

• The preferred treatment for primary brain tumors is the maximal safe surgical removal of the tumor followed by radiotherapy and chemotherapy [6].
• Temozolomide or the combination of procarbazine, lomustine, and vincristine (PCV) are commonly used to treat newly diagnosed, low-grade brain tumors [5].
• Steroids such as dexamethasone are often prescribed to control cerebral edema and manage symptoms in brain tumor patients [3].

Emerging Therapies

• Tovorafenib (Ojemda) has been approved by the FDA for patients 6 months and older with relapsed or refractory pediatric low-grade glioma [7].
• Vorasidenib has shown promise in improving progression-free survival and reducing tumor size in IDH1/2+ glioma patients [8].

Treatment Considerations

• The treatment of adult CNS tumors depends on the type of tumor, and a multidisciplinary team approach is often necessary for effective management [15].
• Targeted therapy, such as PLX038, may be explored in phase 2 trials to assess its effectiveness in slowing tumor progression in patients with MYC or MYCN amplifications [10].

Incidence and Mortality Rates

• The combined incidence of brain and other CNS tumors in the United States was 6.2 per 100,000 people per year, with a mortality rate of 4.4 deaths per 100,000 people per year (2016-2020 data) [12].
• Worldwide, approximately 308,102 new cases of brain and other CNS tumors were diagnosed in the year [12].

References

[1] Alomari, S. (2021). Valproic acid as an antiepileptic drug in patients with brain tumors.

[3] Not specified (2024).

[4] Not specified (2024).

[5] Not specified (2024).

[6] Not specified (2024).

[7] Not specified (2024).

[8] Not specified (2024).

[10] Not specified (2024).

[12] Surveillance, Epidemiology, and End Results (SEER) Program database.

[15] National Comprehensive Cancer Network (NCCN) Guidelines for Central Nervous System (CNS) Cancers.

The differential diagnosis of obsolete central nervous system (CNS) adult tumors involves considering various types of lesions that were previously classified as CNS tumors but are no longer considered malignant or neoplastic in nature.

Historical Context Prior to the 2021 WHO classification, certain CNS tumors were classified as malignant or neoplastic. However, with the introduction of molecular diagnostics and revised classification criteria, some of these tumors have been reclassified as non-neoplastic or benign conditions.

Obsolete Tumors Some obsolete CNS adult tumors that are no longer considered malignant or neoplastic include:

• Primitive Neuroectodermal Tumor (PNET): This term has been abandoned since 2016 and replaced with more specific diagnoses, such as medulloblastoma and other CNS embryonal tumors [6].
• CNS Embryonal Tumors: These rare and mostly found in young adults and children, representing less than 5% of primary central nervous system (CNS) tumors [5].

Differential Diagnosis When considering the differential diagnosis of obsolete CNS adult tumors, it is essential to analyze the imaging features in the context of the clinical presentation of the patient. A systematic approach should be based on:

• Imaging patterns: Anatomical features, such as intra- vs. extra-axial lesions, and specific characteristics like round nodular enhancing lesions or wedge-shaped cortical lesions [10].
• Clinical history: Prior medical conditions, symptoms, and mode of presentation can help narrow down the differential diagnosis.
• Molecular diagnostics: Incorporating molecular characteristics in the diagnosis of CNS tumors is crucial for accurate classification.

Relevant Changes The 2021 WHO classification introduced significant changes by including molecular characteristics in the diagnosis of CNS tumors while keeping other approaches to tumor characterization, like histology and immunohistochemistry [12].

References

[5] Crainic, N. (2023). Glioneuronal and neuronal tumours are rare and mostly found in young adults and children, representing less than 5% of primary central nervous system (CNS) tumors.

[6] Osborn, A. G. (2022). The 2021 WHO classifies CNS embryonal tumors into 2 groups: medulloblastoma and other CNS embryonal tumors (the term “primitive neuroectodermal tumor has been abandoned since 2016).

[10] A wedge-shaped cortical lesion, involving the frontal lobe, with a history of seizures and focal neurological deficits.

[12] The World Health Organization (WHO) published the fifth edition of the WHO Classification of Tumors of the Central Nervous System (CNS), introducing relevant changes by including molecular characteristics in the diagnosis of CNS tumors.