A 40-year-old patient, Ramu, has on X-ray an expansile solitary tumour in the centre of the femoral metaphysis with endosteal scalloping and presence of punctate calcification. The most likely diagnosis is
Osteoclastoma
Osteoid Osteoma
Osteosarcoma
Chondrosarcoma
Ans-D Chondrosarcoma Chondrosarcoma - secondary changes in pre-existing cartilaginous lesion a. Common in forth and fifth decades. b. Patient may present as dull ache or a gradually enlarging lump, medullary lesion may presents as a pathological fracture c. Site - It may arise in any bone but is common in flat bones such as scapula, pelvis and ribs. X-ray - shows erosion of the cortex and bone destruction the tumor matrix may have mottled calcification typical of a cartilaginous tumor d. Primary chondrosarcoma: - shows a radiolucent area with central flecks of calcification, Rarely the tumour appears as a globular mass on the surface of the bones e. Secondary chondrosarcoma - shows bony exostosis, often surrounded by clouds of patchy calcification in the otherwise unseen lobulated cartilage cap, A tumour that is very large and calcification that is very fluffy and poor outlined are suspicious features.