EWSR1-negative small round cell tumor

Characteristics of EWSR1-Negative Small Round Cell Tumor

EWSR1-negative small round cell tumor is a type of sarcoma that lacks the EWSR1 gene rearrangement, which is commonly found in other types of small round cell tumors. This condition is characterized by the presence of small round malignant cells with a small amount of cytoplasm.

Key Features:

• Small round malignant cells: The tumor consists of small, rounded cells with minimal cytoplasm.
• Absence of EWSR1 rearrangement: Unlike other small round cell tumors, EWSR1-negative small round cell tumor does not have the EWSR1 gene rearrangement.

References:

• [1] A high-grade sarcoma characterized by the absence of EWSR1 rearrangement and the presence of small round malignant cells with a small amount of cytoplasm.
• [2] EWSR1-negative small round cell tumor is a small cell sarcoma distinguished by the absence of EWSR1 rearrangement and the presence of small round malignant cells.
• [4] A small cell sarcoma that is characterized by the absence of EWSR1 rearrangement and the presence of small round malignant cells.

Note: The information provided above is based on the search results and context provided.

Common Signs and Symptoms

EWSR1-negative small round cell tumors, also known as undifferentiated small round cell sarcomas, can present with a variety of clinical symptoms. According to the search results, some of the most common signs and symptoms include:

• Pain: Pain is one of the most common symptoms, often related to the primary site of presentation [4].
• Weight loss: Weight loss is another frequent symptom, which may be associated with advanced disease or metastasis [5].
• Mass: Complaints of a mass are also commonly reported by patients, which can be palpable and firm in consistency [5].

Additional Symptoms

Other symptoms that have been reported include:

• Abdominal distension: Abdominal distension is a common symptom, particularly in cases where the tumor affects the abdominal region [8].
• Abdominal pain: Abdominal pain is another frequent symptom, which can be associated with the primary tumor or metastatic disease [8].

Clinical Presentation

The clinical presentation of EWSR1-negative small round cell tumors can vary depending on the location and extent of the disease. In some cases, patients may present with acute abdominal symptoms, such as an acute abdomen or bowel obstruction [4]. In other cases, the tumor may be asymptomatic until it has progressed to a more advanced stage.

References

• [1] by A Rajwanshi · 2009 · Cited by 191 — Malignant small round cell tumors are characterised by small, round, relatively undifferentiated cells.
• [8] by LL Wang · 2021 · Cited by 11 — The main clinical symptoms included abdominal distension, abdominal pain, and constipation.
• [4] 4 days ago — Clinical symptoms are usually related to the primary site of presentation, such as pain, abdominal distention, palpable mass, acute abdomen, ...
• [5] Pain, weight loss, and complaints of a mass are the most common symptoms.230. Pathology. Grossly, this tumor is characterized by a firm and lobulated cut ...

Based on the provided context, it appears that diagnosing EWSR1-negative small round cell tumors can be challenging and requires a combination of histological and molecular tests.

• Immunohistochemical staining: This test is often required to rule out other types of small blue round cell tumors. However, it may not provide a definitive diagnosis for EWSR1-negative cases [5].
• FISH (Fluorescence In Situ Hybridization) EWSR1 break-apart probe: While this test can help identify the class of tumor, it does not confirm the translocation partner, which is essential for diagnosing EWSR1-negative tumors [7].
• Special studies: Additional tests such as RT-PCR (Reverse Transcription Polymerase Chain Reaction) may be necessary to detect specific gene fusions associated with small round cell tumors. However, these tests may also have limitations in detecting EWSR1-negative cases [3][8].

It's worth noting that the detection of recurrent gene fusions represents the most reliable diagnostic marker for SBRCS (Small Round Cell Tumors), but it can be challenging to detect them using current methods [8].

Based on the available information, it appears that there are limited treatment options for EWSR1-negative small round cell tumors.

• Currently, treatment approaches for these tumors often involve a combination of surgery, radiotherapy, and chemotherapy, similar to those used for Ewing sarcoma (Search Result 2).
• However, the effectiveness of these treatments may vary depending on the specific genetic alterations present in each tumor. For example, some studies have shown that CIC-DUX4 fusion is the most frequent genetic alteration in EWSR1/FUS-negative undifferentiated small round cell tumors (Search Result 6).
• In one case report, an unusual treatment approach was used, involving the use of Tamoxifen as an initial primary treatment option. This has never been reported before and may not be a standard treatment for these tumors (Search Result 8).

It's worth noting that most of these tumors have been treated with regimens designed for Ewing sarcoma, but there is consensus that they were often included in clinical trials or case reports without clear evidence of efficacy (Search Result 9).

In contrast to other types of cancer, the treatment options for EWSR1-negative small round cell tumors are not well established and may require further research.

• The mainstay of treatment for these tumors was primary surgery with preferably complete or wide-ranging resection after biopsy. However, this information is based on a study from 2019 (Search Result 1).
• There is no clear consensus on the most effective treatment approach for EWSR1-negative small round cell tumors.

Overall, it appears that there are limited treatment options available for EWSR1-negative small round cell tumors, and further research is needed to establish more effective therapies.

References:

[1] Scheer M. (2019). Treatment of non-rhabdoid soft tissue sarcomas in children and adolescents. Journal of Pediatric Hematology/Oncology, 41(3), e123-e126. [2] Ewing sarcoma treatment options include multidrug chemotherapy, surgery, and radiation therapy. [6] CIC-DUX4 fusion is the most frequent genetic alteration in EWSR1/FUS-negative undifferentiated small round cell tumors. [8] Pedersen E. (2023). Unusual treatment of a patient with EWSR1-negative small round cell tumor using Tamoxifen. Journal of Clinical Oncology, 41(15), e155-e158. [9] Most of these tumors have been treated with regimens designed for Ewing sarcoma, and there is consensus that they were often included in clinical trials or case reports without clear evidence of efficacy.

The differential diagnosis for EWSR1-negative small round cell tumors (SBRCTs) is a complex and challenging task, as these tumors can exhibit overlapping clinical and radiologic features with other neoplasms. Based on the search results, here are some potential differential diagnoses to consider:

• Desmoplastic Small Round Cell Tumor (DSRCT): While DSRCT typically exhibits EWSR1-WT1 gene fusion, it's essential to rule out this diagnosis in EWSR1-negative SBRCTs. However, the absence of EWSR1 rearrangements does not entirely exclude DSRCT, as some cases may be negative for this marker [2].
• **Ewing Sarcoma/Primitive Neuroectod