Case Presentation A 12-year-old girl with a known history of polyarticular juvenile idiopathic arthritis (JIA) presented with a 3-month history of progressive, painless, bilateral proptosis, more pronounced in the left eye. Medical History Juvenile idiopathic arthritis (polyarticular, seronegative) Previously treated with NSAIDs only Ophthalmological Examination Bilateral axial proptosis (left > right) (Figure 1) Mild upper eyelid swelling Normal visual acuity (10/10 both eyes) Preserved ocular motility, no diplopia Fundus examination: Unremarkable Onset was insidious, afebrile, and painless Exophthalmos was non-reducible No orbital thrill detected Figure 1: Clinical photographs of the patient at presentation (Source: Cureus)  Laboratory Findings CRP: 184.92 mg/L ESR: 45 mm/hr Hemoglobin: 8.8 g/dL Leukocytes: 14.65 × 10³/µL Platelets: 465 × 10³/µL TSH: 0.614 µIU/mL Immunology Infectious…