Rhabdomyosarcoma is a rare cancer involving the orbit, head and neck, most often found in children. It is the most common primary orbital malignancy in children. This typically presents with proptosis (eye bulging out) or eyelid swelling over days to weeks. The diagnosis is made with a biopsy and treatment includes surgically removing most of the tumor followed by chemotherapy and radiation to the area. The prognosis has improved considerably over the last few decades and is usually favorable.