plasmacytoma /plaz′məsītō″mə/ pl. plasmacytomas, plasmacytomata, a focal neoplasm containing plasma cells that may develop in the bone marrow, as in multiple myeloma, or outside the bone marrow, as in tumors of the viscera and the mucosa of the nasal, oral, and pharyngeal areas. Also called peripheral plasma cell myeloma, plasma cell tumor.
