Protein filled cysts of the ciliary epithelium are found in a patient with multiple myeloma. The supposedly characteristic white appearance of the cysts was found to be a laboratory artifact due to formaldeyhyde fixation. Immunoelectrophoretic studies of the cyst contents demonstrated the presence of gamma globulin which was identical to that present in the patient's serum. Associated proteinaceous cysts of the choriod plexus of the brain were also present.
Johnson BL, Storey JD. Proteinaceous Cysts of the Ciliary EpitheliumI. Their Clear Nature and Immunoelectrophoretic Analysis in a Case of Multiple Myeloma. Arch Ophthalmol. 1970;84(2):166-170. doi:10.1001/archopht.1970.00990040168008