The most commonly seen primary orbital tumour in children is

Rhabdomyosarcoma It is a highly malignant tumour of the orbit arising from the extraocular muscles. It is the most common primary orbital tumour among children, usually occurring below the age of 15 years (90%). Clinical features: It classically presents as rapidly progressive proptosis of sudden onset in a child of 7-8 years. Massive proptosis due to rhabdomyosarcoma located in the superonasal quadrant (mimmicking acute inflammatory process). The clinical presentation mimics an inflammatory process. The tumour commonly involves the superionasal quadrant; but may invade any pa of the orbit. Ref:- A K KHURANA; pg num:-394