obsolete recurrent peripheral primitive neuroectodermal tumor

Recurrent Peripheral Primitive Neuroectodermal Tumor (PNET): An Obsolete Term

Peripheral Primitive Neuroectodermal Tumors (PNETs) are a type of cancer that originates from the neuroectoderm, a layer of cells in the developing embryo. In the past, PNET was used as a term to describe a specific subtype of Ewing's sarcoma, a rare and aggressive bone cancer.

Characteristics

• Malignant: PNETs are malignant tumors that can spread to other parts of the body.
• Neuroectodermal origin: They originate from the neuroectoderm, a layer of cells in the developing embryo.
• Small, undifferentiated cells: PNETs are composed of small, undifferentiated neuroectodermal cells.

Subtypes

• Ewing's sarcoma: A rare and aggressive bone cancer that is often associated with PNET.
• Askin tumor: An uncommon malignant neoplasm of a neuroectodermic origin that arises from the soft tissues of the thoracopulmonary wall.

Treatment and Prognosis

• Surgery, chemotherapy, and radiation therapy: Treatment options for PNETs include surgery, chemotherapy, and radiation therapy.
• Poor prognosis: Unfortunately, PNETs have a poor prognosis due to their aggressive nature and tendency to spread quickly.

The term "peripheral primitive neuroectodermal tumor" is now considered obsolete in medical literature. Instead, the more specific terms "Ewing's sarcoma" or "Askin tumor" are used to describe these types of cancers.

References

• [2] A rare malignancy of the neuroectoderm, they are fast-growing small round cell neoplasms, occurring very rarely in the kidney. PNETs account for ...
• [7] PNET is a malignant neoplasm comprising small, undifferentiated neuroectodermal cells, and the common origin sites are the long bones, such as the femur and ...
• [8] Primitive neuroectodermal tumors (PNETs) are malignant tumors of neuroectodermal origin, in the Ewing's sarcoma (EWS) family, and is categorized ...
• [10] Definition: Not Available; Synonyms. recurrent Askin's tumor; recurrent Ewing's sarcoma/peripheral primitive neuroectodermal tumor.

Common Signs and Symptoms

The signs and symptoms of recurrent peripheral primitive neuroectodermal tumor (pPNET) can vary from person to person, but some common ones include:

• Headache and vomiting: These are often the first symptoms to appear, as the tumor grows and puts pressure on the brain [1].
• Dizziness and intracranial hypertension: As the tumor grows, it can cause increased pressure in the skull, leading to dizziness and other symptoms of intracranial hypertension [1].
• Conjunctivitis and decreased eye movements: In some cases, patients may experience rapidly progressive visual loss, conjunctivitis, and decreased eye movements due to the tumor's growth [3][6].
• Fever, weight loss, and cachexia: Patients with recurrent pPNET may also experience constitutional signs and symptoms such as fever, weight loss, and severe cachexia [4][10].

Other Possible Symptoms

In addition to these common symptoms, patients with recurrent pPNET may also experience:

• Abdominal pain: Some patients may present with generic and ordinary symptoms like abdominal pain [7].
• Lethargy, confusion, and disorientation: In some cases, the tumor's growth can lead to lethargy, confusion, and disorientation [8].

Important Clinical Observations

It is worth noting that each patient's experience with recurrent pPNET may be unique, and not all patients will exhibit all of these symptoms. Additionally, some patients may experience severe cachexia and weight loss, which was not mentioned in previous cases [10].

References:

[1] X Hu (2022) - The clinical manifestations of intracranial EWs/PNETs usually include headache, vomiting, dizziness, and other symptoms of intracranial hypertension.

[3] B Geramizadeh (2020) - The patient developed rapidly progressive visual loss, decreased eye movements, and conjunctivitis within a week.

[4] Constitutional signs and symptoms such as fever, weight ...

[6] B Geramizadeh (2020) - The patient developed rapidly progressive visual loss, decreased eye movements, and conjunctivitis within a week.

[7] C Baccaro (2023) - Patients generally present no tumor-related specific symptoms, instead presenting only generic and ordinary ones such as abdominal pain,

[8] PK Duffner (1981) - He then remained clinically stable for 6 months, then demonstrated lethargy, confusion, and disorientation.

[10] On the other hand, the severe cachexia and weight loss reported in our patient was not mentioned in previous cases.

Diagnostic Tests for Obsolete Recurrent Peripheral Primitive Neuroectodermal Tumor

Recurrent peripheral primitive neuroectodermal tumors (pPNETs) are rare and aggressive malignancies that require prompt and accurate diagnosis. While the term "primitive neuroectodermal tumor" is no longer used in modern classifications, the diagnostic tests for these tumors remain crucial for effective management.

Imaging Studies

Computed Tomography (CT) scans and Magnetic Resonance Imaging (MRI) are essential imaging modalities for diagnosing and staging pPNETs. These studies help determine the extent of tumor spread, potential pulmonary invasion, and other critical factors that influence treatment decisions [6].

• CT scans can reveal hyperdense lesions compared to surrounding gray matter, as seen in PNET/EWS on CT [1].
• MRI provides detailed images of the tumor's relationship with surrounding structures, aiding in surgical planning.

Histopathology and Immunohistochemistry

The definitive diagnosis of renal ES/PNET is based on histopathological examination and immunohistochemical analysis of resected specimens [3]. These tests help confirm the presence of Ewing's sarcoma/PNET characteristics, such as CD99 expression.

• Histologically, tumor tissue consistent with the diagnosis of retroperitoneal primitive neuroectodermal tumors has been confirmed immunohistochemically [9].

Other Diagnostic Tests

Peripheral blood count, baseline serum chemistry screening, and urinalysis are typically normal in patients with pPNETs. However, tumor biomarker tests (alpha fetoprotein, serum lactate dehydrogenase) may be elevated in some cases [8].

In conclusion, a comprehensive diagnostic workup for recurrent peripheral primitive neuroectodermal tumors involves imaging studies (CT and MRI), histopathology, immunohistochemistry, and other supportive tests. These findings are essential for accurate diagnosis and effective management of this rare and aggressive malignancy.

References:

[1] Context 1 [3] Context 3 [6] Context 6 [8] Context 8 [9] Context 9

Based on the search results, it appears that there are limited treatment options available for recurrent peripheral primitive neuroectodermal tumors (PNETs). However, some potential drug treatments have been explored.

• Thalidomide: According to search result [6], thalidomide has been investigated as a maintenance therapy option for PNET. While the long-term antitumor effects of thalidomide need further study, it may provide a choice for treatment in some cases.
• Crizotinib: Search result [5] mentions that crizotinib led to a sustained response in a patient with refractory primitive neuroectodermal tumor arising from an immature teratoma. This suggests that targeted therapy with crizotinib may be effective in certain cases of PNET.
• Ifosfamide and etoposide: Search result [8] reports on the effectiveness of combination chemotherapy with ifosfamide and etoposide in patients with Ewing's sarcoma or primitive neuroectodermal tumor of bone. While this treatment approach is primarily associated with Ewing's sarcoma, it may also be relevant for PNET.
• Anti-angiogenic drugs: Search result [13] mentions that the long-term use of anti-angiogenic drugs may constitute a new treatment option for maintaining anticancer treatment in PNET.

It is essential to note that these treatment options are not standard and may require further investigation. The management of peripheral PNETs often relies on therapeutic approaches derived from Ewing sarcoma family, as there are no specific guidelines for this rare malignancy (search result [12]).

In summary, while there are limited treatment options available for recurrent peripheral primitive neuroectodermal tumors, some potential drug treatments have been explored. These include thalidomide, crizotinib, ifosfamide and etoposide combination chemotherapy, and anti-angiogenic drugs. However, further research is needed to establish the efficacy of these treatments in this specific context.

References: [5], [6], [8], [12], [13]

The differential diagnosis for an obsolete recurrent peripheral primitive neuroectodermal tumor (PNET) primarily consists of other small round cell lesions, including:

• Neuroblastoma metastases
• Lymphoma
• Primitive neuroectodermal tumors (PNETs)
• Ewing's sarcoma/PNET
• Gastrointestinal stromal tumor (GIST)

These conditions can be challenging to distinguish from PNET due to their similar histological and immunohistochemical features. A thorough examination of the patient's medical history, imaging studies, and histopathological findings is essential for an accurate diagnosis.

In particular, Ewing's sarcoma/PNET is a significant differential diagnosis for PNET, as it shares many similarities with PNET in terms of its clinical presentation, histology, and immunohistochemical profile. However, the presence of specific genetic markers, such as the EWS-FLI1 translocation, can help differentiate between these two entities.

Other conditions that may be considered in the differential diagnosis for an obsolete recurrent PNET include:

• Gastrointestinal stromal tumor (GIST)
• Lymphoma
• Neuroblastoma metastases

It is essential to note that a definitive diagnosis of PNET requires a combination of clinical, radiological, and histopathological findings, as well as molecular analysis.

References: [4] [8] [9] [10] [11]

Note: The numbers in square brackets refer to the context numbers provided.