Orbital Manifestations of Immunoglobulin G4-Related Disease in Bilateral Lacrimal Glands, Optic Nerves, Trigeminal Nerves, and Maxillary Sinuses.

Immunoglobulin G4 (IgG4)-related disease is characterised by numerous aggregates of IgG4-positive plasma cells in multiple organs. We report two patients who had bilateral proptosis associated with extensive inflammation bilaterally in lacrimal glands, optic nerves, trigeminal nerves, and maxillary sinuses. The patients were treated as idiopathic orbital inflammation syndrome with corticosteroid pulse therapy. As symptoms relapsed upon tapering, a reassessment of immunohistochemical stains of the lacrimal glands confirmed the diagnosis of IgG4-related disease. During 2 years of follow-up, the inflammation regressed spontaneously without any medical treatment in the first patient; however, inflammation in the other patient progressed, and he lost his vision. The extensive orbital involvement, characteristic pathological findings, and slowly progressive clinical course might help practitioners differentiate orbital IgG4-related disease from presumed idiopathic orbital inflammation syndrome.