Pathology of paediatric bone tumours

Primary bone tumours account for less than 0.2% of all neoplasms but malignant bone tumours represent the third most common cause of cancer deaths in children and adolescents. The rarity of bone tumours in itself is a diagnostic challenge but is compounded by the number of tumour subtypes on top of which the imaging and histological features of degenerative and reactive processes, and benign bone tumours can simulate bone sarcomas. Furthermore, even in children bone lesions may represent metastatic disease. Hence the assessment of a bone tumour in a child or adolescent should be performed in a specialist referral bone tumour centre which has access to a multidisciplinary team and molecular diagnostic tests: the latter provides greater diagnostic accuracy. It is now appreciated that germline alterations occur more commonly than previously recognised in children and young adults presenting with osteosarcoma and Ewing sarcoma. Awareness of this is important as genetic counselling and screening may be appropriate. In this article epidemiology, radiology, pathology, genetics, treatment and prognosis of most commonly encountered bone tumours among the paediatric population are reviewed