For 3 patients, there was refinement or reassignment of the diagnosis: MYOD1 mutation (sclerosing rhabdomyosarcoma), MDM2 and CDK4 amplification (change of diagnosis from biphenotypic sinonasal carcinoma to parosteal osteosarcoma), and VHL mutation (change of the diagnosis from spindle cell tumour with mesenchymal character to sarcomatoid renal cell carcinoma). The gene discussed is MDM2; the disease is spindle cell neoplasm.