Probable IgG4-related Orbital Disease Masked by Exuberant Ocular Surface Pseudoepitheliomatous Hyperplasia.

A 40-year-old woman presented with a mass in her OS for 2 years. Examination revealed a large conjunctival lesion on the nasal bulbar conjunctiva OS and a small upper tarsal conjunctival lesion in the OD. Biopsy OD revealed inflammatory granulation tissue, and OS revealed pseudoepitheliomatous hyperplasia with granulation tissue. The lesion responded well to steroids. She was lost to follow-up and returned with an enlarged lesion with orbital extension and corneal perforation. Orbital exenteration was performed. The entire conjunctiva showed extensive epithelial downgrowth and mononuclear round cell infiltrates, predominantly plasma cells admixed with neutrophils suggestive of aggressive pseudoepitheliomatous hyperplasia. Orbital tissue showed ill-defined granuloma formation with acute on chronic inflammation and plasma cells. The tissue IgG4/IgG ratio was 34%, suggestive of probable IgG4-related orbital disease. Based on this case, we conclude that IgG4-related orbital disease can rarely cause conjunctival and scleral inflammation with secondary pseudoepitheliomatous hyperplasia-like changes.