<prompt> Bilateral proptosis is common inCavernous hemangiomaRhabdomyosarcomaA-V communicationsOrbital cellulitis  <response>: C i.e. A-V communications Cavernous hemangioma, capillary hemangioma, dermoid cyst, rhabdomyosarcoma, fibrous histiocytoma, and orbital cellulitisQ mostly cause unilateral proptosis. AV communications eg carotid - cavernous fistula are usually unilateral but may become bilateral contralateral alsoQ. 