<prompt> Soap bubble appearance is seen in:OsteoclastomaOsteochondromaEwing sarcomaLymphoma  <response>: Ans: a Osteoclastoma Ref: Maheswari, 3rd edSoap bubble appearance is seen in osteoclastomaClassical radiological featuresSoap bubble appearance- OsteoclastomaOnion peel appearance- Ewing sarcomaSunray appearance- OsteosarcomaCodman triangle- OsteosarcomaTrethowan signSlipped capital femoral epiphysisAneurysmal sign- TB spineLoss of horizontal striations and prominent vertical striations- Hemangioma vertebraChicken wire calcification- Chondrosarcoma 