Myelomatous involvement of the dura mater: a rare complication of multiple myeloma.

A case of myelomatous involvement of the dura mater is reported. The patient presented with blurring of vision in the right visual field and left sided facial numbness. A magnetic resonance imaging scan of the head revealed extensive infiltration of the dura mater. Cerebrospinal fluid (CSF) analysis showed no plasmacytosis and although there was a raised CSF protein concentration, no paraprotein band was detected, despite the presence of serum paraprotein. The infiltration of the dura mater is likely to have arisen by spread from contiguous bone lesions, contrasting with the pattern of spread seen in myelomatous involvement of the leptomeninges, which probably occurs through haematogenous seeding of the meninges. Leptomeningeal involvement is associated with a very poor prognosis; however, this patient had a favourable response to combined chemotherapy and cranial radiotherapy, suggesting that myelomatous involvement of the dura mater should be considered as a distinct complication of myeloma.