Extramedullary plasmacytoma extensively affecting the sella turcica and paranasal sinuses.

We report a 62-year-old Japanese male who complained of double vision and showed clear boundary mass extending to the clivus, intrasella, suprasella, ethmoidal sinus and sphenoid sinus on neuroimaging. The tumor mass was partially resected via transsphenoidal approach and was diagnosed as the extramedullary plasmacytoma by IgA immunostaining and electron microscopy. Making diagnosis from the imaging findings was difficult in this rare case, but immunohistological and electron microscopic examinations were useful for pathological diagnosis.