Occult Nasolacrimal Duct Obstruction Secondary to IgG4-Related Ophthalmic Disease

A 68-year-old man with known history of IgG4-related disease presented with a 1-year history of mucoid discharge OD and progressive proptosis OS. MRI showed diffuse enlargement of the left lacrimal gland along with prolonged infiltrative changes involving the left extraocular muscles, supraorbital nerve, and infraorbital nerve. No identifiable masses were noted in either nasolacrimal drainage system on MRI. Due to clinical evidence of nasolacrimal duct obstruction, a right external dacryocystorhinostomy was performed along with biopsies of the right lacrimal sac and left lacrimal gland. Immunohistochemical stains identified IgG4-positive plasma cells in the biopsy of the right lacrimal sac indicative of secondary acquired nasolacrimal duct obstruction despite the absence of mass forming lesions on exam and nasolacrimal imaging. This report is the first to describe nasolacrimal drainage system IgG4-related ophthalmic disease involvement in an otherwise clinically and radiographically normal appearing tear drainage system.