<prompt> The most common cause of bilateral proptosis in children is:Cavernous hemangiomaFibrous HistiocytomaChloromaRhabdomyosarcoma  <response>: The most common cause of bilateral proptosis in children is not definitively established, but metastatic neuroblastoma andor leukemia should be considered. Common causes of bilateral proptosis in children are congenital skeletal deformities followed by lymphoma, leukemia and other lymphoproliferative disorders. Chloroma is a solid tumor consisting of myeloid leukemic blasts. Of all the options given it is the best answer. Ref: The Massachusetts Eye and Ear Infirmary review manual for Ophthalmology - Page 186; Surgical Atlas of Orbital Diseases - Page 52. 