Characteristics of orbital multiple myeloma: a case report and literature review.

Multiple myeloma is a plasma cell malignancy that destroys skeletal, renal, and neurological function. Orbital involvement is rare, but has been considered an initial presentation for the malignancy. Furthermore, an association between the subtype of multiple myeloma and the likelihood of orbital infiltration has been suggested. We present a case of an orbital mass that was a recurrence of multiple myeloma. A literature search was performed to evaluate the presentation characteristics of orbital multiple myeloma, plasmacytoma and primary (or solitary) extramedullary plasmacytoma. Past reports were analyzed for age, sex, symptoms at presentation, time from symptom onset to presentation, prior diagnosis before presentation for orbital symptoms, radiological characteristics, immunoglobulin subtype, and survival times. Less than half of published cases had orbital multiple myeloma as the primary presentation. Proptosis is the major presenting sign of orbital multiple myeloma, and radiological evaluation shows that the majority of masses originate in the superotemporal quadrant. The dominant immunoglobulin subtype was IgG.