Corneal deposits as an alerting sign of monoclonal gammopathy: A case report

Purpose. To report the clinical and histopathologic findings of the corneal deposits in a patient with monoclonal gammopathy. Methods. Amorphous corne al deposits developed bilaterally in a 55-year-old woman. The corneal butto n obtained during penetrating keratoplasty was analyzed histologically, imm unohistochemically, and ultrastructurally. Results. The patient was diagnos ed as having monoclonal gammopathy because of the elevation of serum immuno globulin G (IgG) and kappa light chain. Histologic evaluation disclosed tha t the deposits were eosinophilic, periodic acid-Schiff positive, and staine d red with Masson's trichrome. Immunohistochemical examination showed that these deposits reacted positively for IgG and the kappa light chain. Electr on microscopy showed electron-dense deposits composed of parallel fine fila ments with a periodicity of 10-13 nm. Conclusions. We conclude from the imm unohistochemical results that monoclonal gammopathy can lead to corneal dep osits that are dense enough to decrease vision. Because monoclonal gammopat hy may be a life-threatening disease and early diagnosis is important, opht halmologists should be aware that corneal deposits can be an alerting sign of monoclonal gammopathy.