Benign osseous tumour. Usually less than 1.5cm. Up to 10% of all bone tumours (occurs in talus and calcaneus up to 8% of time). M>F
Usually in children and younger adolescents.
Present with local bone pain, usually worse at night and is dramatically relieved by aspirin. Due to vascular elements, vasodilators (eg alcohol) generally increase symptoms
X-ray - oval or round radiolucent nidus, surrounded by large dense uniform reactive/sclerotic zone.
May resolve spontaneously