Background: Involvement of orbital structures by immunoglobulin G4-related disease (IgG4-RD) is not uncommon. We conducted this study to evaluate the clinicopathologic features of orbital IgG4-RD.
Material/methods: This was a retrospective, clinicopathologic study. Clinical records, light microscopic features, results of immunostaining with IgG & IgG4 and laboratory findings were reviewed in 16 patients diagnosed with orbital IgG4-RD.
Results: Eleven patients had a bilateral disease, and the lacrimal gland was involved in 14. Dense sclerosis, plasma cell aggregates and dense lymphoplasmacytic infiltrate were seen in all patients. Serum IgG4 titre was elevated in 12 patients. Nine patients responded completely to glucocorticoid treatment. Five patients had a relapse on discontinuation of treatment.
Conclusion: Orbital IgG4-RD is a distinct clinicopathologic entity requiring increased awareness and needs to be differentiated from other orbital lymphoproliferative lesions.