Intrasellar solitary plasmacytoma terminating in multiple myeloma: a report of a case including electron microscopical study.

A case of multiple myeloma is reported that presented as a solitary plasmacytoma of the bone of the sella turcica. The diagnosis was established by electron microscopy in conjunction with the immunoperoxidase technique. The patient succumbed 37 months after the diagnosis was made. The relation between solitary plasmacytoma of bone and multiple myeloma is discussed. The differential diagnosis of intrasellar tumors may pose serious problems to the surgical pathologist. In difficult cases the value of the immunoperoxidase technique and electron microscopy is emphasized.