<prompt> Expansile lytic lesion with fluid-fluid levels within the metaphysis of fibula seen in CTMRI in an early adolescent female is typical of:Giant cell tumorAneurysmal bone cystHemangiomaFibrous dysplasia  <response>: Ans BFluid fluid levels can be seen in both ABC and GCT but key to remember here is the age. ABC is tumour of adolescence while GCT appears only after fusion of epiphyseal plates. 