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

Objective: To report the clinical and histopathologic findings of the corneal deposits in a patient with monoclonal gammopathy.

Methods: Amorphous corneal deposits developed bilaterally in a 55-year-old woman. The corneal button obtained during penetrating keratoplasty was analyzed histologically, immunohistochemically, and ultrastructurally.

Results: The patient was diagnosed as having monoclonal gammopathy because of the elevation of serum immunoglobulin G (IgG) and kappa light chain. Histologic evaluation disclosed that the deposits were eosinophilic, periodic acid-Schiff positive, and stained red with Masson's trichrome. Immunohistochemical examination showed that these deposits reacted positively for IgG and the kappa light chain. Electron microscopy showed electron-dense deposits composed of parallel fine filaments with a periodicity of 10-13 nm.

Conclusions: We conclude from the immunohistochemical results that monoclonal gammopathy can lead to corneal deposits that are dense enough to decrease vision. Because monoclonal gammopathy may be a life-threatening disease and early diagnosis is important, ophthalmologists should be aware that corneal deposits can be an alerting sign of monoclonal gammopathy.