<prompt> A 37 year old female presents to the clinic with a 3 month history of pain in her left index finger. X-ray of the hand shows a mass. Which is the most common bony tumor of hand?EnchondromaChondroblastomaGiant cell tumourOsteoid osteoma  <response>: Enchondroma is the most common tumor of the phalanges of the hand. In the hand it most commonly affects the proximal phalanges 40-50 followed by metacarpal bones 15-30, middle phalanges 20-30 and terminal phalanges 5-15. Plain Xray shows a purely radiolucent lesion. The bony coex is usually thinned and and is expanded in an uniform fashion. Pathologically it appear as lobules of blue white or blue grey hyaline cailage that are most commonly fragmented from the curettage procedure. Ref: Ohopaedic Oncology: Diagnosis and Treatment By Ernest U. Conrad, page 69 