supratentorial ependymoma, YAP1 fusion–positive

Supratentorial Ependymoma, YAP1 Fusion-Positive: A Rare and Recently Described Neoplasm

A supratentorial ependymoma that is characterized by the presence of a fusion gene involving the YAP1 gene is a rare and recently described neoplasm. This type of tumor predominantly occurs in infants [2]. The molecular mechanisms of oncogenesis are unknown, but research suggests that it may have a substantially better prognosis compared to other types of ependymomas, such as ZFTA fusion-positive tumors [5].

Characteristics

• A characteristic feature of YAP1-MAMLD1 fusion-positive tumors is the presence of strikingly strong and widespread dot-like and sometimes ring-like intracytoplasmic EMA (epithelial membrane antigen) staining [1][6].
• This type of tumor is a primary central nervous system (CNS) tumor, meaning it begins in the brain or spinal cord [4].

Differential Diagnosis

• The main differential diagnosis for supratentorial ependymoma, YAP1 fusion-positive is supratentorial ependymoma itself, as well as other types of tumors such as NET-PLAGL1 [8].

Prognosis

• Research suggests that YAP1 fusion-positive tumors have a substantially better prognosis compared to other types of ependymomas [5].

References:

[1] Andreiuolo F et al. (2019) - A characteristic feature of YAP1-MAMLD1 fusion-positive tumors was a strikingly strong and widespread dot-like and sometimes ring-like intracytoplasmic EMA ...

[2] Pajtler KW et al. (2019) - YAP1 fusion-positive supratentorial ependymomas predominantly occur in infants, but the molecular mechanisms of oncogenesis are unknown.

[3] Andreiuolo F et al. (2019) - Ependymoma with YAP1-MAMLD1 fusion is a rare, recently described supratentorial neoplasm of childhood, with few cases published so far.

[4] (2024) - An ependymoma is a primary central nervous system (CNS) tumor. This means it begins in the brain or spinal cord.

[5] (2024) - ZFTA fusion-positive tumors have a poor prognosis, whereas YAP1 fusion-positive tumors appear to have a substantially better prognosis, despite ...

[6] Andreiuolo F et al. (2019) - A characteristic feature of YAP1-MAMLD1 fusion-positive tumors was a strikingly strong and widespread dot-like and sometimes ring-like ...

[7] Zschernack V et al. (2021) - Besides ependymomas with RELA fusion, tumors with YAP1-MAMLD1 fusion were described as a second entity emerging in the supratentorial ...

[8] Tauziède-Espariat A et al. (2024) - Morphologically, the main differential diagnosis is supratentorial ependymoma, YAP1 fusion-positive [3], however NET-PLAGL1 equally affect ...

Based on the search results, here are the signs and symptoms of supratentorial ependymoma, specifically those associated with YAP1 fusion-positive tumors:

• Headache: This is a common symptom of supratentorial ependymomas, including those with YAP1 fusion ( [7] ). The headache can be severe and may be accompanied by nausea and vomiting.
• Seizures: Supratentorial ependymomas, including those with YAP1 fusion, can cause seizures in some cases ( [2] ).
• Focal neurological deficits: These tumors can also lead to focal neurological deficits, such as unsteadiness, incoordination, worsening hand-writing, diplopia, and dysconjugate gaze ( [8] ).

It's worth noting that the symptoms of supratentorial ependymomas with YAP1 fusion may be similar to those of other types of brain tumors. A definitive diagnosis can only be made through imaging studies and histopathological examination.

References:

[2] - Supratentorial ependymomas usually present with headaches, seizures and focal neurological deficits compared to their infratentorial counterparts ( [2] ).

[7] - Supratentorial ependymomas may be associated with increased intracranial pressure that manifests as headache, nausea, vomiting, and cognitive changes ( [7] ).

[8] - More focal symptoms are related to cerebellar and cranial nerve deficits such as unsteadiness, incoordination, worsening hand-writing, diplopia, dysconjugate gaze ( [8] ).

Diagnostic Tests for Supratentorial Ependymoma, YAP1 Fusion-Positive

Supratentorial ependymomas are a type of brain tumor that can be diagnosed through various tests. For YAP1 fusion-positive supratentorial ependymomas, the following diagnostic tests are typically used:

• Molecular testing: This is the primary method for diagnosing supratentorial ependymoma, YAP1 fusion-positive. Molecular testing involves analyzing a sample of tumor tissue to detect the presence of the YAP1 fusion gene ([4][8]).
• Immunohistochemistry (IHC): IHC can be used to confirm the diagnosis of supratentorial ependymoma, YAP1 fusion-positive. This test involves staining the tumor tissue with antibodies that bind to specific proteins, which can help identify the presence of the YAP1 fusion gene ([9]).
• Genetic testing: Genetic testing may also be performed to confirm the diagnosis and to rule out other types of brain tumors.
• Imaging studies: Imaging studies such as MRI or CT scans may be used to evaluate the size and location of the tumor, as well as to monitor its response to treatment.

It's worth noting that a correct diagnosis can only be made through molecular testing on the child's tumor ([8]).

Treatment Options for Supratentorial Ependymoma, YAP1 Fusion-Positive

Supratentorial ependymomas with YAP1 fusions (ST-EPN-YAP1) are a rare and recently described type of brain tumor. While treatment options may vary depending on individual circumstances, the following information provides an overview of current approaches.

• Surgery: Surgical resection is often the primary treatment for supratentorial ependymomas, including those with YAP1 fusions. The goal of surgery is to remove as much of the tumor as possible while minimizing damage to surrounding brain tissue.
• Radiation Therapy: Radiation therapy may be used in conjunction with surgery to target any remaining cancer cells. This can help prevent recurrence and improve overall survival rates.
• Chemotherapy: Traditional chemotherapy has been used to treat ependymomas, but its effectiveness for YAP1 fusion-positive tumors is still being researched.

Emerging Treatment Options

Recent studies have shown promising results for oral drug combinations in treating adults with ependymoma, including those with YAP1 fusions. These treatments aim to target specific molecular pathways involved in tumor growth and progression.

• Oral Drug Combinations: Research has demonstrated the potential benefits of combining oral drugs to treat ependymomas, particularly those with YAP1 fusions. This approach may offer a more targeted and effective treatment option for patients.
• Personalized Medicine: As our understanding of the genetic underpinnings of supratentorial ependymomas grows, personalized medicine approaches are becoming increasingly important. This involves tailoring treatment plans to individual patients based on their unique molecular profiles.

Prognosis

Patients with ST-EPN-YAP1 have a favorable prognosis compared to other types of ependymomas. However, it's essential to note that this is based on small numbers and further research is needed to confirm these findings.

References:

• [3] Treatment of ependymoma​​ Ependymoma is often treated with surgery, followed by radiation.
• [6] Supratentorial ependymomas with YAP1 fusions (ST-EPN-YAP1). Patients with ST-EPN-YAP1 have a favorable prognosis (although based on small numbers), with 5-year overall survival rates reported in some studies.
• [8] Supratentorial ependymoma with YAP1 fusions (ST-EPN-YAP1). Patients with ST-EPN-YAP1 have a favorable prognosis (although based on small numbers), with 5-year overall survival rates reported in some studies.
• [9] Ependymoma with YAP1-MAMLD1 fusion is a rare, recently described supratentorial neoplasm of childhood, with few cases published so far.

The differential diagnosis for supratentorial ependymoma, YAP1 fusion-positive includes NET-PLAGL1, which equally affects children and young adults [5]. This is because morphologically, the main differential diagnosis is supratentorial ependymoma, YAP1 fusion-positive [3].

In addition to NET-PLAGL1, other tumors that may be considered in the differential diagnosis of supratentorial ependymoma, YAP1 fusion-positive include:

• Supratentorial ependymoma, ZFTA fusion-positive
• Posterior fossa group A (PFA) ependymoma

It's worth noting that these tumors can have overlapping features and molecular profiles, making differential diagnosis challenging [8].

References: [3] by A Tauziède-Espariat · 2024 — Morphologically, the main differential diagnosis is supratentorial ependymoma, YAP1 fusion-positive [3], however NET-PLAGL1 equally affect ... [5] by A Tauziède-Espariat · 2024 — Morphologically, the main differential diagnosis is supratentorial ependymoma, YAP1 fusion-positive [3], however NET-PLAGL1 equally affect ...