Which of the following is assosciated with poor prognosis in Ewings sarcoma DELETE
**Core Concept**
Ewing's sarcoma is a malignant bone tumor characterized by the presence of a specific chromosomal translocation, t(11;22)(q24;q12), which leads to the fusion of the EWS and FLI-1 genes. This genetic abnormality is a hallmark of the disease and plays a crucial role in its pathogenesis. The prognosis of Ewing's sarcoma is influenced by various factors, including tumor size, location, and the presence of metastasis.
**Why the Correct Answer is Right**
The correct answer is associated with poor prognosis in Ewing's sarcoma due to its role in tumor progression and metastasis. The presence of metastasis is a significant indicator of disease severity and is often associated with a poorer outcome. In Ewing's sarcoma, metastasis to distant sites such as the lungs, bones, and liver is a common occurrence, and its presence is a key factor in determining the prognosis.
**Why Each Wrong Option is Incorrect**
* **Option A:** Age is an important prognostic factor in Ewing's sarcoma, but it is not the correct answer. While older patients may have a poorer prognosis, age alone is not a definitive indicator of poor prognosis.
* **Option B:** Tumor size is an important prognostic factor in Ewing's sarcoma, but it is not the correct answer. Large tumors are associated with a poorer prognosis, but the presence of metastasis is a more significant indicator of poor prognosis.
* **Option D:** Histological response to chemotherapy is an important prognostic factor in Ewing's sarcoma, but it is not the correct answer. While a poor histological response to chemotherapy is associated with a poorer prognosis, the presence of metastasis is a more significant indicator of poor prognosis.
**Clinical Pearl / High-Yield Fact**
The presence of metastasis in Ewing's sarcoma is a significant indicator of poor prognosis, and its detection is crucial for determining the disease stage and treatment plan. Metastasis can be detected using various imaging modalities, including CT scans, MRI, and bone scans.
**Correct Answer:** C.