The radiology of bone changes in rhabdomyosarcoma.

Rhabdomyosarcoma usually presents as a soft tissue mass, which may invade adjacent bone. However, the patient presents occasionally with bony metastases. Recognition of these is important for staging and management. Fifty-eight cases have been reviewed; 14 of these had local bone invasion by the soft tissue tumour. All bones involvel were flat bones; 12 showed permeated bone destruction and two showed geographic destruction. Bone expansion was seen in half the involved bones. Twelve of the 58 cases showed secondary bone deposits, which were the presenting feature in five. Although 10 cases had permeated bone destruction, two were very well defined with a wide range of radiological appearances. The radiological differential diagnosis includes neuroblastoma, leukaemic infiltration, lymphoma, histiocytosis X, solitary and multifocal osteosarcoma and other deposits.