Retrobulbar secondary plasmacytoma: a case report and systematic review of the literature

Multiple myeloma is described by the proliferation of malignant plasma cells, in which orbital involvement is rare. In this report, we collected all cases with orbital multiple myeloma from 2009 to 2018 and investigated the characteristics such as sex, age, common orbital symptoms, unilateral or bilateral and different therapeutic options. Also, we reported an uncommon case of multiple myeloma that has been developed into plasmacytoma. Our patient had been initially diagnosed with multiple myeloma, but after a few months, the disease had progressed to secondary extramedullary plasmacytoma in the retrobulbar. Therapeutic measures, such as surgery to prevent its development in the patient's eye, were successful.