PECAM1 and Ewing sarcoma: Negative markers for epithelial (CK7/CK20), melanocytic (S100), and vascular (CD31) tumors excluded other mimics such as Ewing sarcoma or dedifferentiated liposarcoma (negative for MDM2 amplification) or primary adrenal malignancies (negative for neuroendocrine markers like Synaptophysin)[15].