A review of orbital plasmacytomas
Reviewed by James Hsuan

This is a multicentre review of 30 patients with orbital plasmacytomas. There were equal numbers of males and females, and the average age at diagnosis was 57 years. All patients were either already diagnosed with systemic multiple myeloma or it was diagnosed immediately after the orbital disease. The duration of orbital symptoms prior to diagnosis of the plasmacytoma was longer in those without a previous diagnosis of multiple myeloma. Twenty-five patients had unilateral disease. The authors identified four anatomical subgroups: 1) a superolateral bony lesion, 2) single or multiple discrete intraorbital lesions often involving an extraocular muscle, 3) an infiltrative lesion originating within the ethmoid or maxillary sinuses, and 4) an infiltrating lesion originating near the floor of the orbit. The solitary lesions involving extraocular muscles were indistinguishable radiologically from other similar tumours. All but two patients had chemotherapy, over 80% had radiotherapy and 63% had a stem cell transplant. Follow-up data was limited to 21 patients of whom 10 had a complete initial response and 11 a partial response. However, at an average final follow-up of 20 months 54% had died of their disease. Contrary to previous reports this study found no cases of truly isolated orbital plasmacytomas, as all patients were already known to have, or were immediately diagnosed with, multiple myeloma. The survival data suggests a worse prognosis for multiple myeloma patients who develop orbital disease, despite adequate local control. This is a large retrospective series which adds light to a rare condition. 

Clinical presentation and anatomical location of orbital plasmacytomas.
Thuro BA, Sagiv O, Shinder R, et al.
OPHTHALMIC PLASTIC AND RECONSTRUCTIVE SURGERY
2018;34:258-61.