IDH3A and Ollier disease: <h4>Background</h4>This study aims to investigate isocitrate dehydrogenase gene mutations in patients with the non-hereditary skeletal disorders of Ollier disease and Maffucci syndrome, particularly in the extraosseous tumours.<h4>Methods</h4>A total of 16 tumours from three patients with Ollier disease and three patients with Maffucci syndrome were collected.