Rev Bras Oftalmol.2026;85:e0106
Probable pediatric IgG4-related orbital disease presenting as a lacrimal gland mass
DOI: 10.37039/1982.8551.20260106
ABSTRACT
Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory condition characterized by tumefactive lesions, lymphoplasmacytic infiltration, and fibrosis. Orbital involvement is uncommon in children and may mimic infectious dacryoadenitis, idiopathic orbital inflammation, and lymphoproliferative disorders. We report the case of a 13-year-old girl with four days of left periorbital swelling and pain, associated with lacrimal gland enlargement on imaging. Biopsy showed fibrosis, dense lymphoplasmacytic infiltration, and reactive lymphoid aggregates. Immunohistochemistry demonstrated mixed B- and T-cell populations, polyclonal kappa/lambda plasma cells, and up to 31 IgG4-positive plasma cells per high-power field, with an IgG4/IgG ratio of 30%. Serum IgG4 was 76 mg/dL. Although the patient did not fulfill classical adult-based serological and histopathological criteria for definite IgG4-RD, the clinical, radiological, histopathological, and therapeutic-response findings supported a presumptive diagnosis of probable pediatric IgG4-related orbital disease. This case highlights the importance of orbital biopsy, exclusion of differential diagnoses, and cautious interpretation of adult diagnostic criteria in pediatric patients.
