Onion skin periosteal reaction is usually seen in:: (A) Ewings sarcoma, (B) Osteosarcoma, (C) Wilms tumor, (D) Osteoblastoma
Answer is A. Ewing sarcoma Destructive lesion in the diaphysis of a long bone with an "onion skin" periosteal reaction. Originates in the metaphysis of a long bone, but frequently extends for a considerable distance into the diaphysis. Classically, PNET class of tumour, with c-myc positive,having round cells is histology. -Osteosarcoma show codman's triangle, sunray or sunburst appearance as periosteal reaction