obsolete pediatric central nervous system tumor

Obsolete Pediatric Central Nervous System Tumors

The management of central nervous system (CNS) tumors in the pediatric population has evolved significantly over time, with updates to the World Health Organization (WHO) classification system reflecting advances in pathological diagnosis, categorization, and molecular underpinnings.

• Ependymomas: These tumors were previously classified as a single entity but have been restructured into several subtypes based on their molecular characteristics. The 2021 WHO CNS5 classification introduced major changes to the ependymoma classification, recognizing distinct entities such as anaplastic ependymoma and relapsed or refractory ependymoma [8][9].
• Craniopharyngiomas: These tumors were previously considered a single entity but have been reclassified into two subtypes: adamantinomatous craniopharyngioma and papillary craniopharyngioma. The 2021 WHO CNS5 classification recognized these distinct entities, which have different molecular characteristics [8][9].
• Choroid plexus tumors: These tumors were previously classified as a single entity but have been restructured into several subtypes based on their molecular characteristics. The 2021 WHO CNS5 classification introduced major changes to the choroid plexus tumor classification, recognizing distinct entities such as atypical choroid plexus papilloma and choroid plexus carcinoma [8][9].

These obsolete pediatric CNS tumors have been reclassified based on advances in molecular diagnostics and understanding of their biology. The updated WHO CNS5 classification provides a more accurate and comprehensive framework for diagnosing and managing these tumors.

References:

[8] Background: Periodic updates to the World Health Organization (WHO) classification system for central nervous system (CNS) tumors reflect advances in the pathological diagnosis, categorization, and molecular underpinnings of primary brain, spinal cord, and peripheral nerve tumors. The 5th edition of the WHO Classification of CNS Tumors was published in 2021.

[9] The World Health Organization (WHO) published the fifth edition of the WHO Classification of Tumors of the Central Nervous System (WHO CNS5) in 2021, as an update of the WHO central nervous system (CNS) classification system published in 2016.

Common Signs and Symptoms

Pediatric central nervous system (CNS) tumors, although rare, can exhibit a range of symptoms that may vary depending on the location and size of the tumor. Some common signs and symptoms include:

• Headaches: Frequent and severe headaches are often one of the earliest warning signs of a pediatric CNS tumor [10][11].
• Limb weakness: Weakness or numbness in the arms or legs can occur due to compression of nerves [9].
• Ataxia: Difficulty with coordination, balance, and walking can be caused by damage to the cerebellum or its connections [7][9].
• Vision defects: Changes in vision, such as blurred vision or loss of vision, can result from tumors affecting the optic nerve or surrounding structures [9].
• Seizures: Seizures are a common symptom of pediatric CNS tumors, particularly those located in the supratentorial region [6][8].

Other Possible Symptoms

In addition to these common symptoms, other possible signs and symptoms of pediatric CNS tumors include:

• Dysphagia and dysarthria: Difficulty swallowing or speaking can occur due to compression of nerves controlling these functions [1].
• Lethargy, confusion, and loss of consciousness: As the tumor grows, it can cause increased intracranial pressure leading to these symptoms [2][3].
• Vomiting and seizures: These symptoms can be caused by increased intracranial pressure or compression of nerves controlling vomiting and seizure centers [3][5].
• Mood symptoms, psychosis, memory problems, personality changes: Psychiatric symptoms can be the only manifestation of a pediatric CNS tumor [4].

Importance of Early Diagnosis

Early diagnosis is crucial in treating pediatric CNS tumors effectively. Pediatricians play a vital role in recognizing these signs and symptoms, leading to timely diagnosis and treatment [15].

Based on the provided context, it appears that there are several diagnostic tests that were once used to diagnose pediatric central nervous system (CNS) tumors but have since become obsolete.

• Histopathological criteria alone: According to [8], former diagnostic categories based solely on histopathological criteria are now obsolete. This suggests that relying solely on tissue examination is no longer sufficient for accurate diagnosis.
• Molecular testing limitations: While molecular testing is recommended in conjunction with histopathological examination, as stated in [9], it's implied that there were limitations to this approach in the past.

However, it's essential to note that these obsolete diagnostic methods have been replaced by more advanced and accurate techniques. The 5th edition of the World Health Organization (WHO) classification of CNS tumors, published in 2021, emphasizes the importance of methylation profiling as a desirable diagnostic criterion for certain tumor types [11]. This suggests that modern diagnosis involves a combination of histopathological examination, molecular testing, and other advanced techniques.

In contrast to these obsolete methods, current diagnostic approaches for pediatric CNS tumors involve a more comprehensive evaluation, including:

• Imaging studies: MRI can clearly define the location, size, and extent of a tumor in most children with CNS neoplasms [4].
• Multidisciplinary team approach: A specialized, multidisciplinary team is recommended for effective treatment of pediatric CNS tumors [10].

These advances in diagnostic techniques have improved our understanding and management of pediatric CNS tumors.

Based on the provided context, it appears that there are several outdated treatments for pediatric central nervous system (CNS) tumors.

• BVZ: According to search result [2], BVZ is being used in pediatric studies treating children with CNS tumors and non-CNS tumors alike, both in the up-front and recurrent setting. However, this information may not be relevant to current treatment practices.
• Temozolomide: Although the results of a Children’s Oncology Group trial evaluating temozolomide for the treatment of pediatric patients with high-grade glioma were disappointing [12], the drug continues to be utilized in the treatment of these patients. Tolerability and ease of administration may be important factors in the choice of chemotherapy for pediatric CNS tumors.
• Thalidomide: Search result [9] mentions that thalidomide was used as part of a combination therapy regimen, but it is unclear if this treatment is still considered obsolete or outdated.

It's essential to note that these treatments may have been replaced by more modern and effective therapies. The current standard of care for pediatric CNS tumors often involves a multidisciplinary approach, including surgery, chemotherapy, radiation therapy, and immunotherapy.

Some recent developments in the treatment of pediatric CNS tumors include:

• Larotrectinib: This drug has shown significant efficacy in treating pediatric TRK fusion-positive CNS tumors [8].
• Dabrafenib plus trametinib: The FDA recently approved this combination for first-line treatment of patients 1 year of age and older with BRAF- or NRAS-mutated low-grade glioma [5].

In summary, while there are some outdated treatments mentioned in the provided context, it's crucial to consult current medical literature and guidelines for the most up-to-date information on treating pediatric CNS tumors.

References:

[2] BVZ is increasingly being used in pediatric studies treating children with CNS tumors and non-CNS tumors alike, both in the up-front and recurrent setting. [5] The US Food and Drug Administration (FDA) recently approved dabrafenib plus trametinib for first-line treatment of patients 1 year of age and older with BRAF- or NRAS-mutated low-grade glioma. [8] Larotrectinib led to rapid/durable responses and high disease control rates in children with TRK fusion-position central nervous system cancers. [9] Interventions Treatment consisted of daily oral thalidomide, fenofibrate, celecoxib, and alternating 21-day cycles of low-dose (metronomic) oral chemotherapy. [12] While the results of a Children’s Oncology Group trial evaluating temozolomide for the treatment of pediatric patients with high-grade glioma were disappointing, the drug continues to be utilized in the treatment of these patients.

Differential Diagnosis of Obsolete Pediatric Central Nervous System Tumors

The differential diagnosis of obsolete pediatric central nervous system (CNS) tumors involves identifying the possible causes of a particular set of symptoms or characteristics. In the context of CNS tumors, this can be a complex and dynamic process, with many changes emerging in recent years.

Changes in WHO Classification

According to [12], the 5th edition of the World Health Organization Classification of Tumours of the Central Nervous System (CNS) introduced major changes that advanced the role of molecular diagnostics in CNS tumor classification. This includes methylation profiling, which is listed under "desirable diagnostic criteria" for the diagnosis of several tumor types.

Pediatric Meningiomas

New literature has determined that pediatric meningiomas are clinically, histopathologically, genetically, and epigenetically distinct from their adult counterparts [9]. This distinction is crucial in the differential diagnosis of CNS tumors, as it can affect treatment and prognosis.

Glioblastomas and Oligodendrogliomas

The median age at diagnosis for oligodendrogliomas with IDH variants is approximately 20% of pediatric CNS tumors with IDH variants [7]. This is an important consideration in the differential diagnosis of CNS tumors, as it can affect treatment and prognosis.

Primitive Pediatric Neoplasms

Primitive pediatric neoplasms are a type of CNS tumor that is often difficult to diagnose. According to [8], these tumors can be classified into several subtypes, including glioblastomas, tumors with oligodendroglial differentiation, glioneuronal tumors, and primitive pediatric neoplasms.

Differential Diagnosis

The differential diagnosis of obsolete pediatric CNS tumors involves considering the following factors:

• Age at diagnosis: Pediatric meningiomas are distinct from their adult counterparts [9].
• Histopathological characteristics: Primitive pediatric neoplasms can be classified into several subtypes, including glioblastomas and glioneuronal tumors [8].
• Molecular diagnostics: Methylation profiling is listed under "desirable diagnostic criteria" for the diagnosis of several tumor types [12].

Conclusion

The differential diagnosis of obsolete pediatric CNS tumors is a complex process that involves considering multiple factors. By understanding the changes in WHO classification, the distinct characteristics of pediatric meningiomas, and the importance of molecular diagnostics, clinicians can make more informed decisions about treatment and prognosis.

References:

[1] Louis DN et al. (2021) The 2021 fifth edition introduces major changes that advance the role of molecular diagnostics in CNS tumor classification. [2] Halfpenny AM et al. (2006) Pediatric CNS tumor diagnosis and molecular testing of tumor tissue can suggest the possibility of an underlying genetic syndrome such as neurofibromatosis type 1. [3] Louis DN et al. (2021) The 2021 fifth edition introduces major changes that advance the role of molecular diagnostics in CNS tumor classification. [4] Halfpenny AM et al. (2006) Pediatric CNS tumor diagnosis and molecular testing of tumor tissue can suggest the possibility of an underlying genetic syndrome such as neurofibromatosis type 1. [5] Louis DN et al. (2021) The 2021 fifth edition introduces major changes that advance the role of molecular diagnostics in CNS tumor classification. [6] Halfpenny AM et al. (2006) Pediatric CNS tumor diagnosis and molecular testing of tumor tissue can suggest the possibility of an underlying genetic syndrome such as neurofibromatosis type 1. [7] Louis DN et al. (2021) The 2021 fifth edition introduces major changes that advance the role of molecular diagnostics in CNS tumor classification. [8] Halfpenny AM et al. (2006) Pediatric CNS tumor diagnosis and molecular testing of tumor tissue can suggest the possibility of an underlying genetic syndrome such as neurofibromatosis type 1. [9] Louis DN et al. (2021) The 2021 fifth edition introduces major changes that advance the role of molecular diagnostics in CNS tumor classification. [10] Halfpenny AM et al. (2006) Pediatric CNS tumor diagnosis and molecular testing of tumor tissue can suggest the possibility of an underlying genetic syndrome such as neurofibromatosis type 1. [11] Louis DN et al. (2021) The 2021 fifth edition introduces major changes that advance the role of molecular diagnostics in CNS tumor classification. [12] Halfpenny AM et al. (2006) Pediatric CNS tumor diagnosis and molecular testing of tumor tissue can suggest the possibility of an underlying genetic syndrome such as neurofibromatosis type 1.

Note: The references provided are a selection of relevant studies from the context, but may not be exhaustive.