plasmacytomaListen to pronunciation(PLAZ-muh-sy-TOH-muh)A type of cancer that begins in plasma cells (white blood cells that produce antibodies). A plasmacytoma may turn into multiple myeloma.Enlarge this image in new windowBlood cell development. A blood stem cell goes through several steps to become a red blood cell, platelet, or white blood cell. Search NCI's Dictionary of Cancer TermsStarts withContainsBrowse:ABCDEFGHIJKLMNOPQRSTUVWXYZ#