A patient with a solitary intracranial plasmacytoma had involvement of the meninges, but not bone. To our knowledge, it represents the tenth reported case of this type. Two of the previously reported cases involved primarily brain substance, while the rest, including this case, involved primarily the meninges. This lesion closely simulated optic neuritis in this initial clinical presentation and then became a steroid-responsive lesion. A discrete band in the gamma region of the agar gel electrophoresis of the cerebrospinal fluid (CSF) was found in the face of a normal, standard CSF and serum electrophoresis, which disappeared after surgery and therapy with radiation. To our knowledge, this has not been reported previously, although an abnormal standard spinal fluid electrophoresis with an increase in the γ-globulin was reported in several of the previous cases. The changing pathological findings in our case are interesting in light of the possible origin of the plasmacytoma.
Kennerdell JS, Jannetta PJ, Johnson BL. A Steroid-Sensitive Solitary Intracranial Plasmacytoma. Arch Ophthalmol. 1974;92(5):393-398. doi:10.1001/archopht.1974.01010010405006