This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
A 45 yrs male presented with an expansile lesion in the centre of femoral metaphysis. The lesion shows Endosteal scalloping and punctuate calcifications. Most likely diagnosis is: 
Select and explain. 
A. Osteosarcoma, B. Chondrosarcoma, C. Simple bone cyst, D. Fibrous Dysplasia
B: Chondrosarcoma
Answer: B: Chondrosarcoma 
Explanation: Middle aged female with expansile lesion in the femoral metaphysis with endosteal scalloping and punctuate calcifications give the diagnosis of chondrosarcoma. Ref: Concise Pathology By Chandrasoma P, Taylor C, 3rd Edition, Page 971; Robbins Pathologic Basis of Disease, 6th Edition, Page 1241; Essential Ohopedics By Maheshwari, 2nd Edition, Page 223