A 10 years old child has lytic lesions in upper femur, the differential diagnosis can be all except :
Plasmacytoma
Browns tumour
Metastasis
Histiocytosis
Plasmocytoma can be easily ruled out.
It is a localized form of multiple myeloma which usually occurs in 5th to 7th decade.
Metastasis, histiocytosis and brown tumor can cause lytic bone lesions in childhood.