Plasma cell myeloma of the skull base: report of two cases.

Plasma cell myeloma (PCM) of the skull base is rarely encountered in neurosurgical practice. PCM has a wide spectrum of pathology, including a quite benign, solitary plasmacytoma (SPC), and an extremely malignant, multiple myeloma (MM) at the two ends of the spectrum. We have described two patients with PCM of the skull base, of which one harbored SPC, and the other progressed to MM.