Bilateral orbital pseudotumor as the initial manifestation of granulomatosis con poliangeítis (GPA) in a child: A case report

Orbital pseudotumor is uncommon in children and may rarely herald anti‑neutrophil cytoplasmic antibody (ANCA)-associated vasculitis. We report a 4‑year‑old girl who presented with progressive bilateral proptosis due to extraconal-intraconal inflammatory masses. Histopathology showed small‑ and medium‑vessel changes with features suggestive of vasculitis, and serology was MPO‑p‑ANCA-positive. Taken together with the clinical-radiologic pattern and exclusion of neoplasm, infection, and histiocytosis, the findings supported a diagnosis of granulomatosis con poliangeítis (GPA) with orbital‑predominant disease. The child improved with high‑dose corticosteroids and cyclophosphamide. This case underscores that an orbital pseudotumor-although rare-can be the sentinel manifestation of systemic vasculitis in pediatrics; early biopsy, targeted ANCA testing, and multidisciplinary management are critical to preserve vision and guide therapy.