[Corneal crystalline deposits in monoclonal gammapathy: a report of two cases].

Corneal immunoglobulin deposits are an unusual complication of lymphoproliferative affections such as monoclonal gammapathy of indeterminate significance, essential cryoglobulinemia, or multiple myeloma. Although uncommon, this crystalline keratopathy may be the first clinical sign of these malignant disorders. We report two cases of paraproteinic crystalline keratopathy: the first case is associated with a multiple myeloma, combined with cryoglobulinemia, and the second case with monoclonal gammapathy of indeterminate significance. In both cases, corneal crystalline deposits appeared before general clinical symptoms. In the first case, the systemic therapy made no change in the biomicroscopic aspect of the corneal deposit, despite immunoglobulin level normalization in the serum. Conversely, in the second case, we noticed a substantial regression of the corneal crystalline deposits as the systemic normalization. A review of the literature clarified the variety of clinical dorms of paraproteinic crystalline keratopathy, the physiopathogenics hypotheses that are currently being discussed, and the possible therapeutic modalities.