Ewing’s sarcoma arises from
**Core Concept**
Ewing's sarcoma is a type of malignant bone tumor that arises from primitive neuroectodermal cells in the bone marrow. It is a highly aggressive and malignant neoplasm that predominantly affects children and young adults.
**Why the Correct Answer is Right**
Ewing's sarcoma is believed to arise from the neural crest cells, which are primitive cells that give rise to the nervous system and other supporting tissues. The exact origin of Ewing's sarcoma is thought to be from the neuroectodermal cells within the bone marrow, which then undergo malignant transformation. This leads to the formation of a highly aggressive and malignant tumor.
**Why Each Wrong Option is Incorrect**
**Option A:** Lymphoid cells are not the primary origin of Ewing's sarcoma, although there may be some lymphoid infiltration within the tumor.
**Option B:** Osteoblasts are the cells responsible for bone formation, not the origin of Ewing's sarcoma.
**Option C:** Chondrocytes are the cells found in cartilage, and Ewing's sarcoma does not arise from these cells.
**Option D:** Fibroblasts are the cells responsible for producing collagen and other fibers, and are not the origin of Ewing's sarcoma.
**Clinical Pearl / High-Yield Fact**
Ewing's sarcoma is a highly malignant tumor with a propensity for metastasis, particularly to the lungs and other bones.
**Correct Answer:** C. Neuroectodermal cells.