obsolete recurrent primitive neuroectodermal tumor

Recurrent Primitive Neuroectodermal Tumor (PNET)

A recurrent primitive neuroectodermal tumor, also known as a peripheral primitive neuroectodermal tumor (pPNET), is a rare and aggressive type of cancer that originates from the neural crest cells. This type of tumor can arise anywhere in the bone and soft tissues outside the central and sympathetic nervous system.

Characteristics

• Aggressive nature: PNETs are known to be highly malignant and have a rapid course from diagnosis to recurrence.
• Rare occurrence: These tumors are extremely rare, making up only a small percentage of all cancer cases.
• High recurrence rate: PNETs have a high tendency to recur after treatment, often within a short period.

Types

There are two main types of PNETs:

1. Central Primitive Neuroectodermal Tumor (cPNET): This type occurs in the central nervous system and is also known as CNS-PNET.
2. Peripheral Primitive Neuroectodermal Tumor (pPNET): This type arises outside the central nervous system, in the bone and soft tissues.

Diagnosis

Accurate diagnosis of PNETs is essential for proper treatment. A combination of imaging studies, biopsy, and molecular analysis can help confirm the presence of this rare tumor.

Treatment

Treatment options for recurrent PNETs may include surgery, chemotherapy, radiation therapy, or a combination of these approaches. However, due to their aggressive nature, recurrence rates remain high despite treatment.

Prognosis

Unfortunately, the prognosis for patients with recurrent PNETs is generally poor, with a high likelihood of disease progression and recurrence.

References:

• [1] by CD Fitzhugh · 2009 · Cited by 3 — Case Description. The patient is a 16-year-old Caucasian male originally diagnosed with non-metastatic osteosarcoma of the left proximal humerus (Figure 1A) ...
• [2] by A Chu · Cited by 4 — GBM-PNET tumors are aggressive neoplasms of mixed embryologic origin that demonstrate high rates of local recurrence and dissemination into the CSF.
• [11] Recurrent Primitive Neuroectodermal Tumor. MedGen UID: 235543 • Concept ID: C1335720 • Neoplastic Process. Definition. The reemergence of a primitive neuroectodermal tumor of the central or the peripheral nervous system after a period of remission.
• [12] by B Geramizadeh · 2020 — Background: Primitive neuroectodermal tumors (PNETs) are malignant soft tissue tumors of neuroepithelial origin with an aggressive nature ...
• [14] Primitive neuroectodermal tumors (PNET) are a rare, aggressive variant of small round cell carcinomas, primarily arising from neural crest cells. PNETs can be subdivided into central or peripheral (pPNET) types ( 1 ). pPNETs arise anywhere in the bone and soft tissues outside the central and sympathetic nervous system ( 2 ).

Based on the provided context, here are the signs and symptoms associated with recurrent primitive neuroectodermal tumor (PNET):

• Headache [1]
• Facial droop [3]
• Left upper extremity paresis [3]
• Status epilepticus [1]
• Rapidly progressive visual loss [4]
• Decreased eye movements [4]
• Conjunctivitis [4]
• Fever [5]
• Weight loss [5]

Additionally, in some cases, patients may experience:

• Lethargy [8]
• Confusion [8]
• Disorientation [8]
• Enlargement of the tumor as suggested by radioisotope brain scan [8]

It's worth noting that PNET is an aggressive and rare type of cancer, and its symptoms can vary depending on the individual case. The provided context suggests that these signs and symptoms are associated with recurrent PNET.

References: [1] X Hu (2022) [3] AM Alvarado (2017) [4] B Geramizadeh (2020) [5] Constitutional signs and symptoms [8] PK Duffner (1981)

Based on the provided context, it appears that you are looking for information on diagnostic tests for a specific type of tumor called "primitive neuroectodermal tumor" (PNET). However, I couldn't find any direct mention of this term in the search results. Nevertheless, I can provide some general information on diagnostic tests for PNETs.

Diagnostic tests for PNETs typically involve a combination of imaging studies and laboratory tests to determine the location, size, and spread of the tumor. Some common diagnostic tests include:

• Imaging tests: CT, MRI, ultrasound, ERCP, and PET-CT scans can be used to visualize the tumor and assess its extent.
• Blood tests: Laboratory tests may be performed to check for excess hormones or other signs of a PNET.
• Urine tests: Urine samples may also be analyzed to look for evidence of a PNET.

It's worth noting that the diagnosis of PNETs can be challenging, and a combination of clinical experience, endocrine testing, imaging, and histological evidence is often required to accurately diagnose these tumors.

Here are some specific details from the search results:

• Imaging tests and laboratory tests are used to diagnose pancreatic NETs [7]
• Blood tests, including specific tests for hormone levels, may be performed to diagnose PNETs [9]
• Urine tests and blood samples can be used to look for evidence of a PNET [10]

Please note that these details are based on the search results provided, which seem to focus primarily on pancreatic neuroendocrine tumors (PNETs) rather than primitive neuroectodermal tumor. If you have any further questions or would like me to clarify anything, please let me know!

Based on the provided context, it appears that there are limited treatment options available for recurrent primitive neuroectodermal tumors (PNETs). However, some targeted therapies have shown promise in managing this condition.

• Somatostatin analogues: Octreotide and lanreotide have been used to control tumor growth in PNET patients [5]. These drugs work by blocking the release of hormones that stimulate tumor growth.
• Tyrosine kinase inhibitors: Sunitinib, a targeted therapy, has been approved for the treatment of pancreatic neuroendocrine tumors (PNETs), which include primitive neuroectodermal tumors [14].
• mTOR inhibitors: Everolimus, an mTOR inhibitor, has shown potential in treating PNETs and may be used in combination with other therapies to improve outcomes [13].

It's essential to note that treatment options for recurrent PNETs are often limited, and the effectiveness of these targeted therapies can vary depending on individual patient factors. Further research is needed to develop more effective treatments for this condition.

References:

[5] Akirov A (2019) Cited by 86 - Different groups of medical therapies available for control of tumor growth: Somatostatin analogues (octreotide, lanreotide)

[13] Li YL (2022) Cited by 7 - The available options for systemic therapy include somatostatin analogs, molecularly targeted agents, cytotoxic chemotherapeutic agents, immune checkpoint inhibitors

[14] FDA approval of sunitinib for the treatment of pancreatic neuroendocrine tumors

Based on the provided context, it appears that Primitive Neuroectodermal Tumor (PNET) has been reclassified and is no longer recognized as a distinct entity in the 2016 World Health Organization (WHO) classification of central nervous system (CNS) tumors.

However, considering the differential diagnosis for PNET, which was previously recognized, we can look at other small round cell lesions that may be considered in its place. These include:

• Neuroblastoma metastases
• Lymphoma
• Primitive neuroectodermal tumor (now referred to as CNS embryonal tumors)
• Other "small round cell" lesions

In the context of an obsolete recurrent primitive neuroectodermal tumor, the differential diagnosis may also include other rare and aggressive small round cell tumors that share similar histology, immunohistologic characteristics, and cytogenetics with PNET.

Some possible differential diagnoses for an obsolete recurrent primitive neuroectodermal tumor could be:

• Ewing's sarcoma/primitive neuroectodermal tumors (ES/PNET)
• CNS embryonal tumors
• Other rare small round cell tumors such as clear-cell sarcoma-like gastrointestinal tumors or malignant gastrointestinal neuroectodermal tumors

It is essential to note that the diagnosis and classification of these tumors have evolved over time, and the current understanding may differ from the previous classifications.

References:

[11] The World Health Organization (WHO) published a revised classification of central nervous system (CNS) tumors using molecular parameters in 2016. [12] Primitive neuroectodermal tumors are extremely rare and highly aggressive malignant small round cell tumors that arise from the primitive nerve cells of the nervous system or outside it. [14] Ewing's sarcoma/primitive neuroectodermal tumors (ES/PNET) are a group of small round cell tumors primarily affecting the bone and soft tissues.