Atypical corneal manifestations of multiple myeloma. A clinical, histopathologic, and immunohistochemical report

A 52-year-old male developed bilateral subepithelial amorphous corneal deposits as well as diffuse noniridescent anterior stromal haze of unknown etiology. The deposits increased in density and a penetrating keratoplasty was performed in one eye when vision became sufficiently compromised. Pathological evaluation of the tissue included light and electron microscopy and immunohistochemical studies. The deposits were identified as monoclonal IgG kappa immunoglobulins and a systemic workup confirmed the diagnosis of a previously unsuspected multiple myeloma. The clinical course was characterized by the noncrystalline nature of the deposits, recurrence of the myeloma protein within the graft, and the poor response of the cornea to systemic therapy. In addition, profound ocular morbidity occurred, with a final visual acuity of 20/200 OD and 20/400 OS.