In search of a disease

Abstract A 10-year-old child presented with right eyelid swelling and a palpable orbital mass. Diagnostic evaluation with the aid of excisional biopsy revealed a pseudo- encapsulated mass associated with high levels of serum perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA). Family history of rheumatic diseases, response to treatment with corticosteroids and immunosuppressant drugs and clinical and histopathological features suggested an orbital autoimmune response in which p-ANCA antibodies were detected, and a diagnosis of probable IgG4-related disease was made.