Unique case of POEMS syndrome with optic neuropathy due to presumed plasmacytoma

The authors report an interesting case of a 43-year-old man with a history of POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy and skin changes) syndrome with chronic bilateral optic disc edema presenting with sudden painless vision loss from 20/40 to hand motions in the left eye.

Brain MRI revealed a suprasellar mass adjacent to the left optic nerve and enhancement of the optic nerve. The mass decreased in size following chemotherapy for myeloma, with some vision recovery. The authors say this represents a unique case of optic neuropathy due to presumed plasmacytoma in osteosclerotic IgA myeloma and POEMS syndrome. They are unaware of any previous reports of an intracranial mass lesion and optic nerve enhancement in POEMS syndrome.

While optic nerve edema occurs in 29 to 55 percent of patients with POEMS, vision loss is relatively rare. The suprasellar mass in this case caused vision loss possibly due to direct compression of the optic nerve, tumor infiltration, ischemia and decreased nerve conductivity by IgA paraproteins.

The patient's chemotherapy consisted of cyclophosphamide, bortezomib and dexamethasone. Vision initially worsened to no light perception in the left eye, with improvement to counting fingers and complete regression of the mass 14 months after presentation.

This radiographic resolution following chemotherapy supports the presumed pathology of plasmacytoma. Radiation to the area was planned to prevent regrowth.