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.