Diagnosis and staging of malignant bone tumours in children: what is due and what is new?

PURPOSE: Although malignant bone tumours in children are infrequent, it is important to know how to properly diagnose and stage them, in order to establish an adequate treatment. METHODS: We present a review of the diagnostic workflow of malignant bone tumours in children, including history and clinical examination, imaging, laboratory tests and biopsy techniques. Moreover, the two most commonly used staging systems are reviewed. RESULTS: History, clinical examination and laboratory tests are nonspecific for diagnosing malignant bone tumours in children. Radiographs remain the mainstay for initial diagnosis, with MRI the modality of choice for local assessment and staging. Fluorine-18 labelled fluoro-deoxy-glucose-positron emission tomography scans provide a noninvasive method to assess the aggressiveness of the tumour and to rule out metastasis and is replacing the use of the bone scintigraphy. Biopsy must be always performed under the direction of the surgeon who is to perform the surgical treatment and after all diagnostic evaluation has been done. Staging systems are useful to study the extent of the tumour and its prognosis. They are expected to evolve as we better understand new molecular and genetic findings. CONCLUSION: When a malignant bone tumour is suspected in a child, it is essential to make a correct diagnosis and referral to an experienced centre. Following an appropriate workflow for diagnosis and staging facilitates, prompt access to treatment improves outcomes. LEVEL OF EVIDENCE: Level V Expert opinion